Download the most current work-in-progress (WIP) version. (It is free, for now.)
It is missing a finished User Interface, Help resources, tutorials, and page layout/printing tools needed for even basic 'in-house' drafting needs.
Since there is no Software Development Kit (SDK) yet available, third-party plug-in development has not even begun. That includes VRay.
That said, the surface creation tools are largely complete and useful. If you use it only for surface modeling, then it might work OK for you. However, to get any real work out the door, you'll need Rhino for Windows to complete that work.
Support is a little different too. Rhino for Windows is a complete, released, production-ready tool, so our support resources are aimed an you getting your work done.
You are welcome to participate in the development, but since Mac Rhino is in development, we are primarily interested in your feedback aimed at finishing the project and getting it released, We aren't focused on you getting production work completed using it.
New builds will come out several times a month during development. Each new build will run for about 60 days but will be replaced long before it times out.