There are many, many image formats today, but one of those that exist that is not supported by Mac OS X is the UIF format, that unlike the mythical DMG or ISO, it cannot be opened and mounted automatically.
The solution is simple, fast and free: UIF2ISO. It is the classic little program made by a programmer who releases it under the GNU license, so we can hardly object to it, if perhaps the most logical thing is to donate.
The operation is super simple and does not deserve any explanationa, it simply consists of opening a UIF image and saving it as an ISO, nothing more.
Download | FIU2ISO4MAC