law: Patents Act, 1970
  9. Provisional and complete specifications 
  (1) Where an application for a patent (not being a convention
  
  application) is accompanied by a provisional specification, a complete
  
  specification shall be filed within twelve months from the date of filing of
  
  the application, and if the complete specification is not so filed the
  
  application shall be deemed to be abandoned:
  PROVIDED  that the complete specification may be filed
  
  at any time after twelve months but within fifteen months from the date
  
  aforesaid, if a request to that effect is made to the Controller and the
  
  prescribed fee is paid on or before the date on which the complete
  
  specification is filed.
  (2) Where two or more applications in the name of the same
  
  applicant are accompanied by provisional specifications in respect of
  
  inventions which are cognate or of which one is a modification of another and
  
  the Controller is of opinion that the whole of such inventions are such as to
  
  constitute a single invention and may properly be included in one patent, he
  
  may allow one complete specification to be filed in respect of all such
  
  provisional specifications.
  (3) Where an application for a patent (not being a convention
  
  application) is accompanied by a specification purporting to be a complete
  
  specification, the Controller may, if the applicant so requests at any time
  
  before the acceptance of the specification, direct that such specification
  
  shall be treated for the purposes of this Act as a provisional specification
  
  and proceed with the application accordingly.
  (4) Where a complete specification has been filed in pursuance
  
  of an application for a patent accompanied by a provisional specification or by
  
  a specification treated by virtue of a direction under sub-section (3) as a
  
  provisional specification, the Controller may, if the applicant so requests at
  
  any time before the acceptance of the complete specification, cancel the
  
  provisional specification and post-date the application to the date of filing
  
  of the complete specification.