Hello. I own a 2013 Challenger R/T It has a posi rear end however is there a chart of what gears is offered??

A Google search brought me various info sites, although I didn't go through all of them to look specifically for a chart. But you can do that to find what you're looking for. From what little I read on a Challengertalk.com thread it appears there aren't too many options.

BTW, you surely don't have a Chevy rear-end do you? That's a posi-track. MoPars are Sure-Grip.