The Russian Orloff is a red Mille Fluer color and the Rhode Island Red is a Solid Red color. The white Mille Fluer patches are recessive so in the first cross you should get all solid red colored birds (but you may discover that your RIR aren't a pure bred and you think and get some variation).
The RIR has a columbian restrictor and Dark Red genes to make the cockerel all red. I am not really familiar with the Russian Orloff, but think that I have seen some with black breasts. If that is the case then you will be splitting the dark red and columbian restrictors with the cross and would get both red breasted and black breasted cockerels.
The Russian Orfloss has a raspberry comb. I am not 100% sure on the genetics of that comb type but think that you will come out with something closer to the raspberry comb on the offspring (but again you may find that you Orloffs aren't as pure bred as you though get a range on the combs).