Rifaz, you haven't mentioned your Category. Neverthless, in 2018, under State Quota, the cut offs for various Categories have been as follows:

General Category: 568

OBC:525

SC: 423

ST: 404

Now this is 2018 data and we do not have 2019 data yet. In 2019, Tamilnadu's cut offs increased on an average of 80-100 per college. Now cut offs change every year and are dependant on various factors such as no.of Candidates appearing for the exam, no.of Candidate's qualified, top NEET score and difficulty of the exam. Now for 2020, based on your Category, if you belong to General/OBC, you should target 600 and if you belong to Reserved Categories, you should target 550 atleast. For help in counselling, you can use our MBBS Companion: https://www.careers360.com/mbbs-companion