THE PATENTS ACT, 1970
Section 17

Power of Controller to make orders respecting dating of application

(1) Subject to the provisions of section 9, at any time after the filing of an application and before the grant of the patent under this Act, the Controller may, at the request of the applicant made in the prescribed manner, direct that the application shall be post-dated to such date as may be specified in the request, and proceed with the application accordingly:

Provided that no application shall be post-dated under this sub-section to a date later than six months from the date on which it was actually made or would, but for the provisions of this sub-section, be deemed to have been made.

(2) Where an application or specification (including drawings) or any other document is required   to be amended under section 15, the application or specification or other document shall, if the Controller so directs, be deemed to have been made on the date on which the requirement is complied with or where the application or specification or other document is returned to the applicant on the date on which it is re-filed after complying with the requirement.