Hey dear, considering your question for neet exam you score seems excellent, as cutofr varies every year, last year the cutoff was so high that students getting 500 marks were  unable to get govt. Mbbs colleges. With 640 marks you can get a well reputed college under AI quota too, just stay tuned to the coinselling. You can also predict your college through this link:

https://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer