Thanks for visiting the Community.
To confirm, are you looking for a Russian Assistant language for Google Home Mini? If yes, please note that the Russian language is not yet supported. We're always looking for ways to improve and we'll take this as feedback and pass it along to the team. I also suggest that you send feedback using your devices by saying, "Hey Google, send feedback" or by following the steps on this link.
Visit this link for the lists of supported languages on the Google Home/Nest speakers.