Hi

As per previous year closing marks at Government Dental Colleges in Tamil Nadu - 

Rajah Muthiah Dental College and Hospital, Annamalai University, Annamalai Nagar - 535 for marks for SC Candidate;

Tamil Nadu Government Dental College & Hospital, Chennai - 541 marks for SC Candidate.

In accordance to that, your marks are way too low to get BDS at any of the Government Dental Colleges in Tamil Nadu under 85% State Quota Seats.

You can always check the same about NEET 2019 Cutoff Tamil Nadu in a greater detail through this link: https://medicine.careers360.com/articles/neet-cutoff-tamil-nadu.

Best of Luck. 

Hope this helps.

Cheers!