Yes Lemmy.ml is the most popular of the tankie instances. They will ban you, remove your posts, etc in most major communities if you say anything negative about CCCP, Russia, Communism, etc.

I can recommend lemmus.org as a very fast and efficient instance. Remember, you don't have to have an account on the instance who's communities you want to access. You can access communities on all instances from any instance. So the policies of your home instance don't really affect you much. They only affect the communities hosted there.