Hello student,

Hope you are in good health, regret to tell you about this as  to JEE MAINS entrance exam you first have to fill the application form correctly fill successful payment of fees then only you will be eligible to give JEE MAINS , but for 2021 the JEE mains examination has being done so there is no change for you this year please prepare this whole year and fill the application form next year to give JEE MAINS.

Hope this helps!Thankyou