No, it is not guaranteed that any Windows emulators will work, because most of these like Parallels have bugs in the OpenGL implementations and so the UCCNC GUI may not appear properly.
We saw it at a few customers, but we do not have MACs and so we can't check or test to see what exact OpenGL functions work incorrectly.
So at current time using MACs with Windows emulators is not supported, you should use a native Windows installation on a PC, a desktop, a laptop or tablet which fits the minimum requirements of the UCCNC which is desribed in the UCCNC manual.
And there is no native OSX version of the UCCNC, because that would require a different code base of the software.
We have long term plans to make the UCCNC platform independent and then it could work on both OSX and Linux, but this is yet just a plan which may or may not happen in the future, I can't promise yet.
And BTW, out of curiosity why would anyone using a MAC to control a CNC? I mean it is far too expensive to get it dirty and full of chips etc. when using the CNC machine. A suitable PC is far cheaper.