Hello!

If you want to contest through the 85% STATE QUOTA, domicile certificate for the state from which you belong is a PRELIMINARY REQUIREMENT. As your nativity to a particular state will be verified at the time of counselling itself . However, you'll be asked to submit your domicile certificate after you are allotted a college based on your merit, just like the other candidates, who gain admission through All India 15% quota.

The gist, you require your domicile certificate especially for 85% state quota.

Hope this helps!