Section 219(1)(iii) in The Navy (Pension) Regulations, 1964
(iii)That applicant may withdraw his application by written notice to the Controller of Defence Accounts (Pensions) despatched within two weeks from the date on which he receives intimation of the revised sum payable on commutation. If the applicant does not withdraw in writing his application within the said period, he shall be presumed to have accepted the sum offered.