In order to register a .RU domain name you must agree to the registry terms set by The Coordination Center for TLD RU/РФ but no local presence requirements exist. In short, almost anyone can register a .RU domain name – and millions have.
As of Q3 2020, almost 6 million .RU domain names were registered. Some of the more popular .RU sites include:
A good visual showing the popularity of .RU domain names is below: