Educational Qualification which you need to have :

• Army Wing of National Defence Academy: Candidates applying for Indian Army must have passed class 12/HSC in 10+2 pattern of School Education or equivalent examination conducted by a State Education Board or a University

• Air Force, Navy and Naval Academy of National Defence Academy: Candidates applying for Air Force, Navy and Naval Academy must have passed class 12/HSC in 10+2 pattern of School Education with Physics and Mathematics conducted by a State Education Board or a University

For more information, you can go through below website -

http://www.competition.careers360.com/articles/nda-eligibility-criteria

Good Luck!!!