I do not know what your caste is but the cutoffs for the government medical college in tamilnadu usually very high and by the state quota 85% you need to score a minimum of 550 and for 15% all India quota without domicile of tamilnadu you need to score in excess of 600 for unreserved candidates and so even for reserved candidates cut off could be a minimum of around 520 for 85% state quota and 584 15% all India quota all the these are subject to variations depending upon the standard of the question paper and relative performance of the other candidates