Gaurav, you haven't mentioned your Category. This is important because every Category has different cut offs. With a score of 503, your rank might be approximately between 45023-51086 . This is an expected rank range: https://medicine.careers360.com/articles/neet-result-marks-vs-rank . In 2019, under State Quota, the cut offs for various Categories have been as follows:

General Category: 406

OBC: 401

SC: 338

ST: 389

So irrespective of your Category, you have decent chances at M. S. Ramaiah with this score. Now this is based on 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. For complete list of colleges that you may have a shot at, please use our College predictor: https://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer