i want to put this on my mac but i dont know how

The Carmageddon page says it's only compatible with Windows - there may indeed be some way to get it to run on a Mac (I don't own a Mac so have no idea),but the vanilla GOG version isn't Mac-compatible.

I'm still trying to figure that one out, too. The GoG version doesn't seem to play nice with Wineskin (a Windows "emulator" for OS X); I can't even get it to the opening animation.

I have the GoG version on my Windows machine, and noticed that it uses DOSBox, so I tried installing it via Wineskin on my Mac and then installing the unpacked game folder in Boxer (a DOS emulator for OS X). It still didn't work. Boxer appears to install Carma successfully, but when you try to load any of the game .exe files, you get as far as the main menu screen (no loading animations or anything), and then nothing. If you try to play the game, it just asks for the game CD-ROM :/ .

According to Wine HQ, the original Windows retail CD-ROM version works with Wine just fine, so there might be something funky about the GoG installer.

[Edited for clarity.]