Hi Ninad , to become an officer at all of the field you mention you have to clear CDS exam or join NDA. And to appear for CDS exam you have to complete your graduation first.

For army maths is not compulsory. While for air force and navy maths is compulsory. 

I hope it will help.

Thanks.

Hello Ninad,

The requirements for entry into NDA is as follows:
Age – 16 ½ to 19½ yrs
Qualification – 12th Class of 10+2 for Army and with Physics and Maths for AF/Navy
Duration of Training – 3 Yrs at NDA and then 1 Yrs at IMA, Dehradun

Technical Entry Scheme -TES(For High School Science Graduates):
The TES entry is open twice a year.
Vacancies Per Course – 85
The requirements for entry into TES is as follows:
Age – 16 ½ to 19 yrs
Qualification – 10+2 Physics, Chemistry & Maths (aggregate 70% and above to apply)
Duration of Training – 5 Yrs 

AIRFORCE-

Eligibility Criteria
Age – 16 ½ to 19 years
Nationality – Indian
Educational Qualifications – 10+2 with Physics and Mathematics. 

NAVY

Eligibility Criteria
Age – 16 ½ to 19 years
Educational Qualifications – 10+2 with Physics and Mathematics. 

Thank you