If you are interested in Indian army then you can apply for any of the entrance exam given below and you can also check the eligibility to apply each of given exam.

NDA

CDS

NDA: National Defence Academy & Naval Academy commonly referred as NDA/ NA is a national level entrance exam conducted by Union Public Service Commission (UPSC)

Eligibility

To Apply for NDA you  must be between 16.5 and 19.5 years of age.

You must have passed class 12 with 10+2 pattern of school education or equivalent examination with Physics and Mathematics by a State Education Board or a University.

For further you can go through with given below link.

NDA

CDS: Combined Defence Services commonly known as CDS is conducted twice a year by Union Public Service Commission (UPSC) for graduate candidates. Appear for CDS, clear the examination appear in the ssb , clear the ssb and medicals, join the academy for the same.

Eligibility

To apply for CDS exam you must be between 20 to 24 Years.

You must be graduate from recognized university.

For further detail you can go through with given below link.

CDS

Please clarify your qualification and if you have given any entrance exam or applied for any entrance exam? What si your 12th class stream?