If the question is really what can RUSSIA do
, then the flip answer really is nothing
. The very short summary of what has already been said before is that you pretty much just have to retreat in a manner that doesn’t allow too many of your men to get wiped out too soon.
The real question is what can the Allies do by turn 6 that will cause the German player to slow down the amount of reinforcements they send to their Russian stack so that the Russians can keep pace with it. I agree with Stalingradski that the Mid East holds more promise than going into France. It’s always extremely tempting to try and shuck somebody up from Gibraltar into Normandy or Norway, but these areas are just too close to the Axis production areas to stage a safe, early invasion. Every territory in Western Europe (basically) has an IC of some kind in it, so no matter how empty it was when you landed, it can instantly fill up with troops exactly when needed. I’ve had a lot of opponents trying out the Don't capture Normandy
strategy, which gives me a chuckle, since Normandy is almost never relevant. The Axis are just denying themselves income and the ability to instantly drop a blocker DD into the English Channel to stop a sudden play up to the W. Germany - Norway belt.
If you are focusing your efforts in the Mid East, then Italy is getting contained, you are sure to be holding Cairo so that the game doesn’t end right away with the loss of Moscow, and you have a place to be building up troops on the mainland that Germany has no easy access to. You can then make a stand in the Caucasus as need be (as already said) or even help India if you have to.
Something I’m still questioning is where to go exactly if you decide you want to pull out of Moscow. The map layout doesn’t favor getting from Moscow to Caucasus ahead of a German stack. I don’t think Russia has any way to get to the Mid East without being attacked and wiped out long before they can arrive. In that case I’m wondering if it better to head right for China or India.