SOLD: I am selling a pretty much new GGB mountain silencer for 13-15 Pro RMKs. I installed it and only ran it a couple of times in the garage, it has never seen the snow.
I know polaris made changes to the mounting bracket in 2013, and people that had cans from their 11s and 12s, had to make an adapter bracket for their cans to fit their 13s-15s. So I would guess it wouldn't be a direct fit the other way either, maybe an adapter of some kind could make it work, probably not worth trying.