In 2019, under State Quota, the cut offs for the colleges that you mentioned under ST Category have been as follows:

Kolkata Medical College: 235

NRS: 280

RG KAR: 249

Now this is 2019 data and cut offs change every year. Cut offs change every year depending on various factors such as no.of Candidates appearing for the exam, no.of Candidates qualified, top NEET score and difficulty of the exam. So for a seat under ST Category, you will need to aim for atleast 325-350. With NEET being pushed by 5 months, preparation time has been longer and so the competition might be tougher.