Are 1997 gsxr 750 parts interchangeable with 2000 gsxr 600 parts?

Yes and no. It depends on the parts that you want to interchange. Most of the plastics will interchange, only one that comes to mind that doesn't is the chain guard. Some of the motor parts will work clutch, oil pan, etc. But the carbs are different. Easiest thing to do if get a hold of a Manual and check the part numbers that you want to switch out, of just do some searching for the parts that your wondering about. There are quite a few sites that are dedicated just to GSX-R / Gixxer bikes.