Your age should be between 16.5 years and the maximum age limit should be 19.5 years. Write now, you are 16 years and 1 month. Only unmarried male candidates born not earlier than January 02, 2002 and not later than January 1st, 2005 are eligible. This is for this year. So you are eligible for NDA 2020, 2021 and 2022 and one session of 2023.