Maybe you had no luck with the demo version you tried.
Here is the link for the demo of last Stable version :
https://render.otoy.com/plugindownloads/8c/5e/16/1e/OctaneRender_for_Maya_OSX_DEMO_9.38.pkg

Here is the Topic for this version ( 3.05.03 - 9.38 ) :
https://render.otoy.com/forum/viewtopic ...

[Tried to post this question once, and it was rejected: "The reported message has the only purpose to advertise for a website or
another product." - Wow. No idea where that's coming from.]

I'm trying the demo plugin (3.04) for Maya (2016.5/2017) with Mac OS 10.11.6, Titan X GPU. IPR rendering ...