After PUC you can Indian Navy either through NDA exam or by becoming Sailor. For appearing in NDA you must be between 16.5 and 19.5. National Defence Academy & Naval Academy commonly referred as NDA is a national level entrance exam conducted by Union Public Service Commission (UPSC) twice a year for recruiting around 800 officers’ vacancies Indian Army, Navy, Air Force. Generally, NDA I & II have approximately 400 vacancies. While for becoming sailor in Indian Navy your age should be between 17 and 21 years of age. Indian Navy sailor exam and you can find details regarding the same on its website.