Tamil Nadu Govt hasn’t declared that they will do admission based on class 12 marks. Tamil Nadu govt recently only passed a decision that they don’t want to conduct neet anymore in their state. Hence the admissions for academic year 2021-22 will be done strictly based on neet scores and not 12th marks.
if you have any further doubts or need clarification please mention your marks and rank in NEET 2021.

And also to predict the college you might get use the college predictor tool right below

https://medicine.careers360.com/neet-college-predictor?utm_source=qna&utm_medium=neet_cp