In case an Indian passport holder has overstayed in the US on B1/B2 visa, by over 6 months, and wants to come on his own back to India, will there be any problems or checks at Dulles airport during return?
Can he be banned to return back?
U.S. does not have any exit checks. You can just go out of the country without any issues. Your exit will be recorded as the airline shares the data with CBP.
However, CBP will record the overstay and you cannot come back easily. If you overstay your visa for more than 180 days (but less than one year), when you depart the U.S. you will be barred from reentering the U.S. for three years. If you overstay your visa for one year or more, when you depart the U.S. you will be barred from reentering the U.S. for ten years.