I don't see any choice into the download but LINUX and MAYA.
The only explanation in the documentation is for Windows.
Could it be a parameter in the installation line that I need to add: octane_maya_demo_2.24.2-7.14.run --install

I'm trying to install the demo version under Maya, but it does not work. The stand alone works fine. I used to have maya 2016, but not anymore. So, I am interested to install Octane for Maya 2015. When I run the installer, I get:

[plalancette@poste-0425 Downloads]$ octane_maya_demo_2.24.2-7.14.run ...