I born on 2 april 2002. Can I apply for TES on next year

hello aspirant,

For the TES 2021, Indian Army invites all the male and unmarried d candidates who have passed 10+2 examination with Physics, Chemistry, and Mathematics as their main subjects. The allowance and the examination are conducted under the joint supervision of Indian Army and Grant of Permanent Commission.

and for the age limit part-

A candidate must not be below 16½ years and above 19½ years on the first day of the month in which the course is commencing, i.e., the candidate should not be born before 01 July 2001 and not after 01 July 2004

so, yes you can apply for it.

hope that helps