I have a Mac, can I run GRLevelX software?

Officially, no, you cannot run it on a Mac.

However, the best option would be to run a copy of Windows via virtualization (VMWare Fusion or Parallels Desktop are recommended) or Boot Camp, which is a separate Windows partition on on your Mac hardware.  NOTE: a valid Windows license is required.

Some people have reported getting it to work with Wine or CrossOver (a paid Wine implementation), or using VirtualBox, an open-source virtualization solution.  While free, your mileage may vary, and are not supported.