I have already installed Russian keyboard layout.
In language support -> installed languages I already have Russian.
But when I open text file with Cyrillic I have encoding problems. This files was created in Windows earlier. With new files I don't have this problem.
Ìàìà ñòðàòåã ñåìåéíûé íàø Åùå óñòðîèò íàì øàáàø Ìû ñ íåé íå óìðåì îò ñêóêè, Çà ýòî öåëóåì åé ðóêè.
UPD. I tried to specify Windows-1251 encoding manually while opening file and Cyrillic has shown correct. I don't have problem in files, which encoding was set as UTF-8.