Hey,

Yes, you need to register for different states separately in order to get admission through 85% state quota in a respective state.

If you want to take admission through 15% All India Quota, Central and Deemed universities, you just need to register through the official site of counselling conducted by DGHS.

To know more about NEET Counselling, you can check here https://medicine.careers360.com/articles/neet-counselling