Exam

Yes, you can appear for NDA exam in class 11th and the first post rank given is Lieutenant in officers.

Yes, GRE is the best exam to study abroad and for scholarship.

In this case, you can be an officer, only if you are a medical MBBS degree holder. Else, you have to crack at least SSB interview to be an officer.

Yes, they have ACC entry for that.

For joining Indian Army, you have many ways. After class 12th, you can apply for NDA TES entries. After graduation, you can apply for CDSE, NCC, UES, TGC, ACC, SCO, PCSl. In all above case, you have to clear SSB interview to get selected. Also, eligibility for all entries is different. Check it with

Dear Uday,
Pimple is not a medical problem. You can definitely join Indian Air Force, if you meet your other eligibility conditions.

You need for pass in all your exam for being eligible for exam.

It will be approximately INR. 3lacs to INR.3 5 lacs .

It generally starts from month of November to first week of March.

You can apply for NDA exam which is conducted twice a year for Navy. You can apply for Navy 10+2 B.Tech entry scheme.