2000 sebring coupe rims?

I need help finding rims for my car. I have stock 17 inch and I am looking for any rims that are compatible in a 15 or 16 inch. I cant seem to find any. I found out it says something about being 17 x 6.5 size and 5 lug 100mm. I don't know what that means but please help or can you direct me to information. Thank you!