DESC:“ROTOR ASSEMBLY OF AN ELECTRICAL MACHINE” FIELD OF THE INVENTION The embodiments herein generally relate to an electrical machine, and more particularly, to a rotor assembly of the electrical machine. BACKGROUND OF THE INVENTION An electrical machine is a device that converts electrical energy to mechanical energy. One of the common performance issues in the electrical machine is overheating. Overheating may harm the electrical machine’s performance. Overheat may demagnetize a plurality of magnets that is present in a rotor. Overheat may affect the magnetic properties of the plurality of the magnets. To avoid the electrical machine from overheating, many systems are available like an air-cooling method and a liquid cooling method. In a conventional method, the electrical machine manufacturers use the air-cooling method to dissipate heat due to losses in the motor. The air-cooling method dissipates heat from the rotor much less than liquid coolant due to its low density and low thermal conductivity. In a recent method, electrical machine manufacturers use the liquid cooling system. In the liquid cooling system, the liquid cooling agent is circulated between the electrical machine’s structure to dissipate heat. The liquid cooling system requires high maintenance due to leakage issues. Leakage of the cooling agent will ruin the entire structure of the electrical machine permanently and need high maintenance. High maintenance may make the system costlier. In addition to that, liquid cooling systems are complex setups. In addition to that, the electrical machine manufacturers use a conventional circular shape of the outer periphery of the rotor which will increase the flux leakage and reduce the average back elf, load torque and increase the torque ripple. A conventional alignment of a plurality of magnets and the shape of the rotor and winding has a larger effect on motor performance/behavior. Due to the unoptimized outer periphery of the rotor, the back-EMF generates higher-order harmonics which affects the drive system heavily. Furthermore, due to unoptimized air-gap flux, the torque generated by the electric machine is less. The shape of the rotor periphery influences the nature of MMF waveform & Noise. So, the conventional technologies are not efficient to optimize the air-gap flux, the back elf, and increasing torque. Hence, there is a need for an improved rotor assembly of the electrical machine to address the aforementioned issues. SUMMARY OF THE INVENTION In view of the foregoing, an embodiment here in provides a rotor assembly of an electrical machine. The rotor assembly of an electrical machine includes a plurality of stacked laminated thin sheets. The plurality of stacked laminated thin sheets includes a plurality of laminated thin sheets. The plurality of laminated thin sheets stacked together to construct the plurality of stacked laminated thin sheets. The plurality of stacked laminated thin sheets stacked together to construct the rotor assembly. The rotor assembly includes a plurality of magnetic slots mechanically configured to provide space for a plurality of magnets. The plurality of magnetic slots positioned on an inner circumference of the rotor assembly. The plurality of magnets positioned at a first predetermined angle to each other. The rotor assembly includes a predetermined-shaped outer periphery. The predator mined-shaped outer periphery includes a plurality of segmented surfaces. The plurality of segmented surfaces includes a first segmented surface, a second segmented surface, a third segmented surface, a fourth segmented surface, and a fifth segmented surface. The plurality of segmented surfaces positioned at a second predetermined angle to each other. The plurality of segmented surfaces is positioned at a reference angle with respect to a center axis of the rotor assembly. In some embodiments, the second predetermined angle is less than 10°. In some embodiments, the reference angle is determined with respect to a reference line from a center axis of the rotor assembly. In some embodiments, the reference angle includes an angle A°, an angle B°, an angle C°, an angle D°, and an angle E°. In some embodiments, the angle C° between the reference line and the third segmented surface is equal to 90°. The angle B° between the reference line and the second segmented surface is less than 90°. The angle A° between the reference line and the first segmented surface is greater than 90°. In some embodiments, the angle D° between the reference line and the fourth segmented surface is less than 90°. The E° between the reference line and the fifth segmented surface is greater than 90°. In some embodiments, the plurality of segmented surfaces starts from 25% to 35% percent length of either end of a length of the plurality of magnets. In some embodiments, the predator mined-shaped outer periphery of the rotor assembly is constructed with minimum material present at the plurality of the segmented surfaces to push flux lines away to an air surface. In some embodiments, the predetermined-shaped outer periphery of the rotor assembly is constructed with minimum material present at the third segmented surface to push flux lines away to an air surface. In another aspect, a rotor assembly of an electrical machine includes a predator mined-shaped outer periphery. The predator mined-shaped outer periphery includes a plurality of segmented surfaces. The rotor assembly includes a plurality of stacked laminated thin sheets. The plurality of stacked laminated thin sheets includes a plurality of laminated thin sheets. The plurality of laminated thin sheets stacked together to construct the plurality of stacked laminated thin sheets. The plurality of stacked laminated thin sheets stacked together to construct the rotor assembly. The rotor assembly includes a plurality of magnetic slots. The plurality of magnetic slots mechanically configured to provide space for a plurality of magnets. The plurality of magnetic slots positioned on an inner circumference of the rotor assembly. The rotor assembly includes an air-gap pocket includes an air-gap and a magnetic bridge. The air-gap, the magnetic bridge, and the air-gap pocket are configured to allow magnetic flux leakage towards the air-gap of the electric machine by allowing less flux leakage to pass through the magnetic bridge. In some embodiments, the air-gap includes one or more inner lines and one or more outer lines. In some embodiments, the one or more inner lines, and the one or more outer lines are parallel. In some embodiments, the one or more inner lines, and the one or more outer lines are inclined to at least one segmented surface of the plurality of segmented surfaces. In some embodiments, the one or more inner lines, and the one or more outer lines are inclined to the third segmented surface of the plurality of segmented surfaces. In some embodiments, the predetermined-shaped outer periphery of the rotor assembly is constructed with minimum material present at the air-gap pocket to push flux lines away to an air surface. These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications. BRIEF DESCRIPTION OF THE DRAWINGS The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which: FIG. 1A & 1B illustrate a perspective and a top view of a rotor assembly according to an embodiment herein; FIG. 2A & 2B illustrate an exploded view of the plurality of magnetic slots and corresponding pole structure of the rotor assembly according to an embodiment here in; FIG. 3A illustrates a sectional view of an air-gap pocket of the rotor assembly according to an embodiment herein; FIG. 3B illustrates a sectional view of an outer periphery of the rotor assembly according to an embodiment herein; FIG. 4A illustrates a sectional view of the plurality of weight reduction cut-outs of the rotor assembly according to an embodiment herein; FIG. 4B illustrates a top view of the rotor with the plurality balancing rings according to an embodiment herein; and FIG. 5 illustrates the perspective view of the rotor assembly with the encoder magnet, and the encoder magnet holder according to an embodiment herein. DETAILED DESCRIPTION OF THE INVENTION The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein. Referring now to the drawings, and more particularly to FIGS. 1 to 5, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments. FIG. 1A & 1B illustrate a perspective and a top view of a rotor assembly100 according to an embodiment herein. The rotor assembly 100 includes a plurality of stacked laminated thin sheets 102, a plurality of magnets 104, a plurality of magnetic slots 106, a plurality of weight reduction cut-outs 108, and at least two keyways 110 (A-B). The rotor assembly 100 of an electrical machine includes a plurality of laminated thin sheets. The plurality of laminated thin sheets stacked together to construct a plurality of stacked laminated thin sheets 102. The plurality of stacked laminated thin sheets 102 stacked together to construct the rotor assembly 100. In one embodiment, the plurality of laminated thin sheets stacked together using a plurality of connecting members112. Each of the plurality of laminated thin sheets includes the plurality of connecting members112. The plurality of connecting members 112 may include a male connecting member and a female connecting member. The female connecting member is positioned on a lower part of the plurality of laminated thin sheets. The male connecting member is positioned on an upper part of the plurality of laminated thin sheets. While stacking, the female connecting member of the plurality of laminated thin sheets positioned on the male connecting member of the plurality of the laminated thin sheets. In one embodiment, the male connecting member is positioned on the lower part of the plurality of laminated thin sheets. The female connecting member is positioned on the upper part of the plurality of laminated thin sheets. While stacking, the male connecting member of the plurality of laminated thin sheets positioned on the female connecting member of the plurality of the laminated thin sheets. The plurality of magnets 104 positioned in the plurality of magnetic slots 106 in such a way adjacent magnetic poles are opposite poles (N-S). The plurality of weight reduction cut-outs 108 positioned a predetermined location of the rotor assembly 100. In one embodiment, the predetermined location may be an axial surface of the rotor assembly 100. The plurality of weight reduction cut-outs 108 is filled with less density and high thermally conductive material. Herein, the plurality of weight reduction cut-outs 108 filled with the less density, and the high thermally conductive material to receive heat energy which is generated by the rotor core and plurality of magnets 104 at the time of rotating. In addition to that, the less density, and the high thermally conductive material protects the plurality of magnets 104 from demagnetization by receiving heat energy from the rotor assembly 100 to avoid the accumulation of heat in the rotor core. Further, the heat energy generated from the rotor core spreads to the plurality of bearings. The less density and the high thermally conductive material increase the life of the plurality of bearings by receiving the heat energy from the rotor assembly 100. Due to design and manufacturing constraints, there may be a chance for the rotor assembly100 with an unbalanced mass. The one or more keyways 110(A-B) are configured to make the rotor shaft symmetric. The one or more keyways 110 (A-B) are configured to lock the rotor with the rotor shaft. The one or more keyways 110(A-B) configured reduce unbalance of the rotor assembly 100. The rotor shaft is fixed on the rotor assembly100 by the press fit process. Since the different poles attracted (E.g., the North Pole and the South Pole), the flux lines originated from the North Pole and end up with the South Pole. The flux lines pass between the rotor and a stator of the electrical machine through an air-gap 114. The plurality of magnets 104 positioned in such a way there will be a first predetermined angle between two consecutive poles at the air-gap pocket 116. In one embodiment, the first predetermined angle may be varied based on number of poles of the rotor assembly 100. The rotor assembly 100 includes an air-gap pocket 116. The air-gap pocket 116includesthe air-gap 114 and a magnetic bridge 118. The air-gap 114, the magnetic bridge 118, and the air-gap pocket 116 are constructed in such a way to allow-less flux leakage to pass through the magnetic bridge 118 which in terms allows the magnetic flux leakage towards the air-gap 114 of the electrical machine. Further, the too-wide magnetic bridge 118 will decrease the flux leakage in to the airgap114 and reduce the back-EMF and torque. So, that area of the magnetic bridge 118is designed in such a way to handle the high magnetic stress when the torque reached the required value. The first predetermined angle depends on an angle between a plurality of tooth tip faces of the stator. In one embodiment, the length of the plurality of magnets 104, and the length of the plurality of the tooth tip faces of the stator are not equal. In another embodiment, the length of the plurality of the tooth tip faces of the stator is lesser than the length of the plurality of magnets 104.An outer periphery of the rotor assembly 100 is constructed in such a way with minimum material present nearby a position where the North Pole and South Pole generate the flux lines. The outer periphery of the rotor assembly100 with minimum material is configured to push the flux lines away from a rotor surface to an air surface. The flux density will be very high when the flux lines are generated and passed to the air surface. The air-gap flux density is optimized by reducing the material present nearby the air-gap pocket 128 where the north pole and south pole generate the flux lines. The outer periphery of the rotor assembly100 includes a plurality of segmented structures 120. Each of the plurality of segmented structures 120 positioned on the outer periphery of the rotor assembly100. In one embodiment, each of the plurality of segmented structures 120 includes a plurality of segmented surfaces 122. In one embodiment, the plurality of segmented surfaces 122 may include, but not limited to a first segmented surface 122A, a second segmented surface 122B, a third segmented surface 122C, a fourth segmented surface 122D, and a fifth segmented surface 122E. The plurality of segmented surfaces 122 may be positioned at a second predetermined angle to each other. The plurality of segmented surfaces 122 may be positioned at a reference angle with respect to a center axis of the rotor assembly 100. In one embodiment, the reference angle may include, but not limited to, an angle A°, an angle B°, an angle C°, an angle D°, and an angle E°. The reference angle is determined with respect to a center axis of the rotor assembly100. In one aspect, the angle C° between the reference line (as shown in Figure 3) and the third segmented surface 122C is equal to 90° (C°=90°). The angle B° between the reference line and the second segmented surface 122B is less than 90° so that B°C°. The fourth segmented surface 122D and the fifth segmented surface 122E are mirror mounted with respect to the second segmented surface 122B and the first segmented surface 122A so that the angle D° is equal to the angle B° and the angle E° is equal to the angle A°. (The angle D° between the reference line and the fourth segmented surface 122D is less than 90° (D°< C°). The angle E° between the reference line and the fifth segmented surface 122E is greater than 90° (E°>C°)). In another aspect, the angle C° between the reference line and the third segmented surface 122C is equal to 90° (C°=90°). The angle B° between the reference line and the second segmented surface 122B is less than 90° (B°< C°). The angle A° between the reference line and the first segmented surface 122A is less than 90° (A°C°. The fourth segmented surface 122D and the fifth segmented surface 122E are mirror mounted with respect to the second segmented surface 122B and the first segmented surface 122A so that the angle D° is equal to the angle B° and the angle E° is equal to the angle A°. (The angle D° between the reference line and the fourth segmented surface 122D is less than 90° (D°< C°). The angle E° between the reference line and the fifth segmented surface 122E is greater than 90° (E°>C°)). In another aspect, the angle C° between the reference line and the third segmented surface 122C is equal to 90° (C°=90°). The angle B° between the reference line and the second segmented surface 122B is less than 90° (B°< C°). The angle A° between the reference line and the first segmented surface 122A is less than 90° (A°