638 is a very good score.

But the cut off every college varies every year due the variation in the number of students participating, the number of seats available and the difficulty level of the questions. So, to predict an exact marks would not be a fair deal.

But according to your marks and previous year cut off list you would get a seat in KGMC in either ways. You can get it through AIQ as well as State quota seat.

You can also get a predict college of NEET by using the link mentioned below

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