Are Mormons banned in Russia?
All foreign missionary activities are restricted in Russia, but the Mormons haven’t faced this sort of ban.
As a side note, Germany has banned the Scientologists. The Russians moved against that cult in 2007, but I haven’t seen anything recently.
Indigenous protestant groups that can trace their history to before the Revolution face some harassment, but generally have legal status. I have known American missionaries who worked in Russia after the downfall of communism that have been denied entry in recent years, either by having visas rejected or by having them ignored when they arrived at the airport in Moscow.