Hey ,
NDA , the National Defence Academy situated admist the western ghats , in Khadakwasla Pune know as the cradle of military leadership young boys fresh out school inducted into the services are trained to be officers in the forces and provided with a graduation degree as well.
Some coaching institutions to clear written exam for the same in  Thiruvananthapuram
1. Seshan's academy
2. The excel trainning academy
I hope this helps !