They can move them anywhere they like, as long as no sea movement is involved and there isn’t already an IC there. Of course, if they’re too close to the front lines they run the risk of being captured. Bear in mind that an IC can only be used to produce units if the territory that it’s in was owned by the USSR at the beginning of the turn.
I was just thinking if Russia wanted to could they move there IC to Norway if they took it. Then they would be some what sheltered from direct German assult and they would be aided by the UK.