Hii!
There are a number of exams and ways you can get into Indian Armed forces. Some of then are -
NDA and naval academy, combined defence services, OTA Etc.,
UPSC CDSE and NTA are the major ways to join.
Also, there is AFMC and MNS for medical career in defence forces.
So, you can choose accordingly as per your eligibility.
The links given below will give you detailed analysis -

https://www.india.gov.in/spotlight/career-defence-and-paramilitary-forces

http://www.joinindianarmy.nic.in/Authentication.aspx

https://www.google.com/amp/s/www.careers360.com/articles/Universities/How-to-join-Indian-Army-Navy-Air-Force/amp

Hope this helps.
Good luck!