Hey hi there buddy,if you got 620 marks, it is most likely that you got rank of around 13000 in all india ,It is most likely that you can get your field of interest  For instance,based on the last year NEET PG Trend its seen that the candidate who scored rank of 13291 got MS Orthopedics under SC quota in Assam medical college dibrugarh under all india quota and if you have state domicile, you can even get better colleges, hope this helps,good luck.