Hello Sachin Tripathy

It will be depends on students appearing for the exam along with you as well as the standard of the question paper which may differ and vary from year to year.As a whole your qualifying marks for the Neet examination as an St candidate would definitely be in excess of 320 out of 720.

Yet it would be good if you want a Government Medical College via the state quota to get a score in excess of 350 to 360 and score in excess of 380 to 400 if you want to get into a Government Medical College via the 15% all India quota. 

Hope it will helpful

Good Luck.