Dear Aspirant,

If you successfully registered for JEE Mains earlier for corresponding sessions of April-May that are now July-august then you don't need to apply again for same, as given on official NTA website. NTA website also states that if some changes are to be made in application , there are instructions given for it in their website.

You might have got Application ID or some roll number which can be used to check any updates on NTA website for JEE Mains.

Please check NTA website for more :

https://jeemain.nta.nic.in/webinfo2021/File/GetFile?FileId=43&LangId=P