Hello Aspirant,

National Defense Academy which is situated in Pune, Maharashtra, they train you for 3 years in your preferred field (Army, Navy, Airforce), after that you have to go to your respective Academy to complete 1 more year of your training like IMA for Army, INA for Navy, AFA for Airforce. So its a total 4 year long process, after that you will posted to your field.

NDA will provide you a graduation degree in your respective field, B.sc for Army and B.tech for Navy/Airforce. This is only thing you need to appear in IAS exam, all Defense forces provides a educational leave to pursue your dream, in that leave you can prepare for your UPSC, IAS examination, its a very tough job.

Good Luck!!!