When your asking which units have Russian, do you mean just the text on the screen, as in the language, or maps of Russia? All units should have the language, but as far as I know they will not come with the maps. Im not too sure if Russia is included with the Europe map pack or not, but only a few units come with the Europe maps anyways. 

The easiest way for you to check for either of these things would be to try out the fully functional demo units in store. You can change the language to Russian and try it out. Note that if any unit has text to speech, any Russian voices will not to be unlocked and may have to be either downloaded and/or purchased to use them... Usually English is only included by default. Hope that helps!