Hi
Your marks are too less to get a medical seat in government college neither medical not dental  in the  highest cutoff state .Last year least marks  to secure a seat from SC category under state quota was 550 marks in perundurai medical College.Remember cutoff varies every year depending on number of students appearing in the exam, difficulty level of the exam, students scoring more than you and your category.
You can know about cutoff of various colleges in Tamil Nadu from link below
https://www.google.com/amp/s/medicine.careers360.com/articles/neet-cutoff-tamil-nadu/amp
Hope this helps