The state domicile while you belong to, you get a right to apply there ie you get a choice filling form in which you've to enroll the colleges from number 1 to 30 as per your choice list and accordingly on merit you may or may not get a seat in these colleges you chose. These state quota reservation comes under 85%. If you need a seat in any other state, you've to apply for the 15% AIQ, and again you've to repeat the same procedure.

to get a detailed information about the procedure, refer to the following site..

https://medicine.careers360.com/articles/neet-counselling

Best wishes. Thank-you.