Hi,

Yes, you can choose not to give JEE for a particular session even after you paid for it. Currently, the application window for April session is open where you can make changes before 4th of April. Also, NTA does refunds the fee that you paid for this session or if you haven't paid for May session yet, the fees can also be roll over to the session.

You can refer to the 11th and 12th question in this link which is the official notice by NTA: https://nta.ac.in/Download/Notice/Notice_20201225121802.pdf

I hope this helped you.