Section 7(b) in The Former Secretary Of State Service Officers (Conditions Of Service) Act, 1972.
(b)no death-cum-retirement gratuity benefits shall be available to or in respect of an I.C.S. member of the Indian Administrative Service unless such member has exercised his option for such benefits before the appointed day in accordance with the orders of the Central Government in that behalf and the benefits admissible to or in relation to an I.C.S. member of the Service who so exercised his option shall be subject to the conditions specified in the said orders and to the same conditions for grant of retirement benefits as are applicable for the time being in the case of other members of the Indian Administrative Service;
