Hii, 

If i see previous year cutoff trends, then your chnces to fetch government medical college through 85% state quote counselling is quite difficult.

Previous year, the cut off was 417 for SC category candidate to get into Toothukudi Medical College, Toothukudi through state quota counselling.

Even the chances to get government dental college with 316 marks is not possible as the previous year last cutoff for sc category was 400 to fetch government seat in Tamil Nadu Govt. D.C. & Hospital, Chennai and Rajah Muthiah Dental College and Hos. , Annamalai.

You can go for private colleges with Lower cutoffs

Visit this link fir more cutoff details :

https://medicine.careers360.com/articles/neet-cutoff-tamil-nadu

Good luck!