Hi Koustuva,

AIIMS is no longer a seperate exam for Medical Aspirants. The admission to all the AIIMS institutes are provided through NEET only. NEET is going to happen on September 2020 and then, the NEET 2021 registration will be started by NTA.

Refer here for more info - https://medicine.careers360.com/articles/neet#What-is-NEET-2020-Exam

NTA website for NEET - https://ntaneet.nic.in/ntaneet/welcome.aspx

Feel free to ask doubts in the Comment Section.

I hope this information helps you.

Good Luck!