Hello Candidate,

Let me tell you that, the Candidates have to fill only one JEE Main application form for all the four sessions. But the  application form fee has to be paid depending on the number of sessions you select to appear.

And don't be worry, if you are not giving the february session exam. You can fill the application form for next sessions, and the form window for those sessions, will open briefly before the exam dates. For more info,  please visit the link given below.

https://www.google.com/amp/s/engineering.careers360.com/articles/jee-main-application-form/amp

Hope it helps.