Hello dear,

Sorry to inform you that now nothing can be done . You have to update it at the time of jee mains only. There is some time given to students to change their form if any mistake is done after filling jee mains form .

Don't lose hope still you have lot of options and only good will come in your way.

Hey Sanjeev.

See u can't do that now as u have been asked earlier only at the time of the registration and while applying ur application u have been asked to take ur reservation criteria if u will be able to produce any kind of poof on behalf of that. Now u can't change that one as it will violate the regulations on the eportal.of the JEE mains. 

Hope u got ur point. Ask if any query. Good luck