Hello Ujjwal Bansal !

The next academic year of MBBS in all medical colleges of India starts on first week of August. However the admission process continues until September thirtieth. 

It depends on when the seat filling procedures of government gets over. If it was delayed the day of opening will also be delayed.

It also depends on the institute to start the new academic year.

It usually starts around end of August or starting of September.

I hope this information was useful for you.

Feel free to ask further.