Section 119(5)(a) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(a)Candidates must undertake not to marry until they complete their full training at the National Defence Academy and later on at the Indian Naval Ships and establishments. A candidate who marries subsequent to the date of his application, though successful at the Services Selection Board or medical examination, shall not be selected for training. A candidate who marries while under training shall be discharged and shall be liable to refund all expenditure incurred on him by the Government.