Cannot Get This Disk Image To Mount!
I picked one of those downloads at random and looked at the .img file inside the .rar archive.  It's a proprietary format.  file and trid have no idea what type it's supposed to be, the former just says "data".  The first four characters of the file are RKFW, presumably for Riko firmware.

GeekPeek.net has a pretty good guide on how to unpack and repack these files using the imgRePackerRK tool from XDA.