There is 15% ALL INDIA QUOTA reservation available whose counselling starts first. You need to apply for ccolleges of other states through this form from any sttaes of India but their cutoffs will be higher than the 85% state quota and it will have a bit higher competition.

Refer to the website below for more detailed information...

https://news.careers360.com/neet-2020-nta-releases-notice-for-15-aiq-state-of-eligibility Best wishes. Thank you.