Render Settings for RenderMan for Maya (RfM) are controlled through the Maya Render Settings dialog. This is accessed through multiple locations:

 

If you've not created a light in your scene, RfM will create a default directional light for you at render time. This is to support the standard Maya Default Light workflow. You must turn this off under the Common Tab if you require a scene with no lights (for example, your scene is lit with emissive objects alone).

 

 

All these options bring up the same dialog which feels familiar to anyone who has used the native Render Settings in Maya. 

When RenderMan is selected as the Maya renderer, the above dialog is shown.   There are 6 tabs at the top for controlling different parts of the renderer.