Section 202(13)(c) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(c)Sick leave. - (i) An officer holding acting rank who is granted sick leave shall retain paid acting rank from the date of first absence from duty for a period of six months (which will include the period of annual leave of the year) or until he is taken on the strength of a ship or establishment and fills a specific vacancy in the authorised complement of that ship or establishment carrying a lower rank, whichever is earlier.