A suit definitely seems too fancy for Chili's.
Dress shirt or blouse over top of a t-shirt or tank top, whatever feels right for you.
I'd say jeans are alright (if they're look good and are clean), if your just going to a bar and grill.

If you want good advice, you'll have to find someone you know personally that can tell you what outfits and colours work well on you.
Just make sure your clothes fit well and are clean.