Hello Rahul,

Joint Admission Counselling is conducted for admissions to IIIT Delhi, NSIT, DTU and IGDTUW(girls only). The application form will be released tentatively in the third week of June. The candidates have to fill this form to be eligible for admission.

As for your question, since the admissions are on the basis if JEE Mains ranks, you cannot change the category while filling the JAC form.

For more information, follow the below link:

Https://engineering.careers360.com/articles/jac-delhi-application-form