Hi Naman,

You can give NDA after your class 12th so that you can get a fair chance in this field. If you are not interested to give NDA due to some weakness on your subject then you must stay tuned to the vacancies releases by air force & army you may apply there also.

But the best way is the NDA selection procedure while in the vacancies method you may face a bit problem as per my knowledge the probability of fair chances is low. Little bit luck is also necessary.

Thanks

All the best.