Can you add a non-VRay light and see if that does anything?
If the mats aren't black, and u can see the interior in a different scene then you might have enabled or disabled something you shouldn't have - double check your light settings incl. any setting related to the windows and interiors, or re-create the scene. I can't be more specific about 3DS stuff
Edit: hide/delete the windows temporarily and do a render. Does that change anything? If not then u defo have messed something up.