hello,

As per the notice of the authority, this year JEE main is being conducted four times in February, March, April and may. After completion of each phase, the application form window will be reopened and candidates can apply for the next phase. Also, you can apply for all the remaining sessions in a single application. The application form of February session has ended. So, after the end of February exam the application portal will reopen and then you will be able to apply for the next sessions.

Check the link below to know more about the procedure

https://engineering.careers360.com/articles/jee-main-application-form

Good luck!