For Indian Navy, go to their official website- https://www.joinindiannavy.gov.in/, then you have to create an account and fill the application form according to your preferred position.                                                         For Airforce, one must have to appear AFCAT examination or NDA to go through this. Application for AFCAT 2020 has been closed. So be ready for AFCAT 2021! Applications will be open by first week of December,2020. Keep a regular update on their website- https://indianairforce.nic.in/ .         For Indian army, go their website https://joinindianarmy.nic.in/login.htm and enter captcha and their will be option for join as officer or JCR/OR enrolment, click to the preferred tab, register yourself and submit your application.

UPSC holds twice a year, which is a exam for the entry into the national defence academy and naval academy, candidates who have completed 10+2 ( PCM) examination are eligible for the exam. The application has already came for Indian army, you can check their official website of Indian army , there you'll see the notification, the last date is 24th September, 2020, job locations are nagpur, jodhpur, udaipur, pali, bannsware, dungarpur, barmer . Indian Navy had last date of submission of application was on 21st August 2020. Indian Air force had last date of submission on 10th September, 2020.