what will be use after qualifying the exam

Hello
NDA Examination is conducted twice every year for admission to National Defence Academy, Khadagwasla and hence on subsequent training join Indian defence forces as officer.
It is a 3 stage process. First is a written exam consisting of MCQ questions based on Mathematics, English and GS. Those who clear the written examination are called for 5 days interview process called SSB. Those who are recommended in the SSB undergo medicals.
Then a final merit list which includes marks of written exam and SSB is released. Those who make it to the final list join NDA for 3 year training.
At NDA cadets of the tri forces, that is Air Force, Army and Navy undergo training together.

Follow this link for more information on NDA
https://www.google.com/amp/s/competition.careers360.com/articles/nda

Good luck