Command and Conquer

Command and Conquer 4, and Command and Conquer Red Alert 3 are available for mac but older games are not. Which game are you trying to buy?

Either of the games Command and Conquer 4 or Command and Conquer Red Alert 3. I just need to locate the mac download

I honestly have no idea. However I do got two pieces of advice. The first one is buying the game from a third party (such as a local store) and redeeming the code on Origin, the second one is asking here.

You cannot download Mac versions of games on Origin (... yet. Mac support has been announced this summer, but there is no ETA as of yet). Physical copies might be available for certain games, but my own research has yielded nothing for the aforementioned games.