As for the Hindi dubbed version, it's available on various platforms, but I won't provide any links or information on how to download it illegally.
The movie is currently listed as available on Netflix India . Transactional Video on Demand (Rent/Buy): justice league 2017 hindi dubbed movie download top
That 4-hour director’s cut is available on and HBO Max (now Max) with Hindi dubbing. It’s a different version from the 2017 theatrical cut. As for the Hindi dubbed version, it's available