hello,

No you can not change your cast category because if you appear in 4 session with different cast category then your application will be rejected as one candidate cannot register itself with different casts. So you have to register yourself with one and only one cast category so that your application may not be cancelled.

hope this will help you.

all the best!!

Hi.

YES you will be allowed to apply for the March session. The application portal will open again after the declaration of result of February JEE Mains then you can register again and apply your EWS Certificate (if the option is provided)

If you have a further specific query please feel free to comment.

Best of Luck.