Will rims on a 91 Chevy Caprice fit Chrysler 300?

No, rims from a 1991 Chevy Caprice will almost certainly not fit a Chrysler 300. While both are American cars, they have different bolt patterns (the number and spacing of the lug nuts), wheel offsets (how far the wheel sits in or out from the hub), and potentially different center bore sizes (the hole in the center of the wheel that fits over the hub). These differences are significant enough to prevent them from being interchangeable. Trying to force them on would be unsafe.