It looks like those rings were done with a 5-axis machine. The Nefertiti pendant could have been done with a 4-axis one, though. Rhino is a CAD program; no mill will directly handle the files it produces. You'll need some kind of CAM program to generate toolpaths from the CAD files, taking into account the tools and other parameters, and generate a G-code file the mill software can execute. RhinoCAM from Mecsoft is a good choice for that, since it plugs into the Rhino workspace, but there are others as well.