Can you play a game without having a graphic card?

Yes, if you mean the game has "NVIDIA" in big letters across the front of the box, and you have an ATI card. If you mean the model it says is required is higher than the one you have, don't give up hope, it might still be possible. It might just be really slow, or you might have to lower the quality a lot. So to give you a short answer, yes, it is possible, but that's not a 100% guarantee.