Hello student,

Now, you are from BC category and having Tamil Nadu domicile please follow the link below to know previous year's cutoffs category wise for both All india quota and State quota. https://medicine.careers360.com/articles/neet-cutoff-tamil-nadu

The following factors on which the cut off of NEET depends are:

1. Total number of students appearing in NEET exam
2. The level of difficulty in the question paper
3. Total number of available seats
4. Rank in the NEET merit list

Now, according to your marks  400 you may not have a chance in govt. medical college but can secure seat in govt. dental college or semi government medical colleges.

Please follow this college predictor tool for more clear vision about the college you have a chance according to your score https://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer