Disney no longer holds the licensing rights to the RCMP's trademarks, including the Mountie likeness. One of the characters I have used for years - Marshall Mountie - traditionally wears a Mountie-like uniform. What I've done to avoid problems is make sure the uniform is not an exact copy of the traditional Mountie uniform and a few years back I dropped the "Mountie" part of his name because that is technically an RCMP trademark.
The RCMP is pretty cool about their traditional uniform appearing in theatre, film, etc. as long as what you're doing is not defammatory. The best thing to do is contact their public relations department and make an enquiry before doing anything that's heavily dependent on a Mountie character.