For Army

go to higher authority of your battalion.

the biggest question is why do u want to leave ur service. if u r medically unfit then that can be shorted out by making an application to the higher authority and thereby declaration that u r medically unfit can be declared only by them. rest if u want to change ur infantry then the same can be done my making a application showing grounds of urs wanting to leave the infantry. But this exit opportunity have very less chances of success.

its not easy to leave Indian defense if you want to leave defense so need to proof medical unfit. Let me tell my personal experience of my father My father was in Indian Air Force he given his service almost 16 years 8 months due to health issue he wants to leave Indian Air Force but they were not allowing so he filed suit against that department with relevant evidence and witnesses. after the judgement then my father got retirement from Indian Air Force.

Pls serve for our country ,kindly donot take wrong decisions

No way to get rid of the army is available. You will be declared as a deserter if you stealthily go out and will be punished for that severe offence. Only way to get out is being declared medically unfit for military service.