Fallout for MAC is also for System 7.1; Unless you plan to run it on an ancient mac... You might be better off with the DOS version or the regular Win95 version, via emulation. (also I'd buy the GOG FO installer for $6, and borrow and old system out of someone's basemant, or look for a $15 thrift shop PC ~97% of them will work just fine ~Fallout really does have looooow system requirements).
Indeed, You'd be better of trying to play via Boot Camp, or running windows in paralells or VM.
And that way you'll also be opening up your gaming choices a bit more