dear prashant,

if you are a 12th appearing or passout student in current year then you can give nda exam.

eligibility criteria for nda exam-

1:for army wing  -Candidates applying for Army Wing of National Defence Academy should be 12th pass or 10+2 pattern of School Education or equivalent examination

2:for Air Force, Navy and Cadet Entry Scheme at the Indian Naval Academy-Candidates applying Air Force and Naval Wings  of National Defence Academy and for the 10+2 Cadet Entry Scheme at  the Indian Naval Academy must be 12 th or equivalent examination   with Physics and Mathematics

if you want to know more information about NDA exam thenyou can go through the below link

https://competition.careers360.com/exams/nda

If you fulfill all requirements then you 'll eligible for NDA (National Defence Academy).

There are Some requirement for NDA as-

Education eligibility criteria-

•For Army wing of NDA-

A candidate should be passed 10+2 from any recognised board.

•For Air force and naval forces of NDA-

A candidate must be passed 10+2 or equivalent exam with the physics and mathematics.

Age limit-

•A candidate should be minimum 16.5 year and max. 19.5 years old.

Physical standards :-

•A candidate should be good physical health and good vision.

•A candidate chest should be well developed.

•The minimum acceptable height is 157 cms (for Air Force is 162.5 cms).

For more details, kindly check below mentioned link-

https://www.google.com/amp/s/competition.careers360.com/articles/nda-eligibility-criteria/amp

Best of luck! !