Dear Sheetal, you haven't mentioned your Category. Neverthless, cut offs change every year and are dependant on varous factors such as no.of Candidates appearing for the exam, no.of candidates qualified, top NEET score and difficulty of the exam. So considering these factors the score you might need for a seat in MBBS are as follows:

General Category: 550-600

OBC:  450-550

SC: 400-450

ST: 350-400

These cut offs are including Private Medical Colleges. Please remember that this is just an assumption and actual marks might vary.