Goblin Commander is the only RTS game I can think of on the Xbox, although the reviews weren't too good for it. Full Spectrum Warrior is a lot like a tactical squad-based first-person RTS game. Kingdom Under Fire: The Crusaders has elements of RTS gameplay like commanding troops and such. Worms Forts: Under Siege is turn based strategy, as is Wrath Unleashed.
So to answer your question, not really.