I have the REN and I had to buy a module to get Uconnect. I bought it wholesale, installed it and had the dealer turn it on.
Strange tho that the Mopar accessory website claims the the RER to be integrated with Uconnect... I guess the dealer should know what you have.
On the lighter side- all you should need is a Mic and to verify the HFC/VR module is enabled in the engineering menu. This can be tricky stuff and you can brick your radio in the engineering mode.
Call another dealer- unless you are certain you have some odd ball RER that no one knows about.