If you are feeling very bold stack the 6 infantry in the east in Bury and send the 2 Moscow tanks to Yakut. This will require Allied assistance but it gives Russia the option of attacking Manchuria on round 2.
As has been stated above the eastern territories are only worth 1 IPC and 3 together add up to 1 Infantry per turn. Also trying to hold or fight over these territories will end up getting the Soviet air force out of position to attack German targets not a good thing.