You can register for DraftKings Casino in Michigan, Connecticut, New Jersey, West Virginia, or Pennsylvania. You can have an account for DraftKings Casino in other states, but you can't place a bet unless you are physically located in one of those legal markets.
You can also bet on sports outside the U.S. on DraftKings Sportsbook in Ontario, Canada. You don't need to be a resident of any of these states to place a bet at DraftKings.