All supporting documents including photograph should be certified by the Indian Embassy or a notary in the home country of the applicant or by the practicing chartered accountant or company secretary or cost accountant.
DIN (Director Identification Number) is a distinct Identification Number which is allocated to an individual who is either the present director of the company or intends to be one in the future.
Under sec 12 of Companies Act, it's mandatory for the companies to have a registered office to maintain the account books, annual returns, statutory registers all under the same roof.