The drawing that I am viewing using DWG TrueView provides dimension in feet and inches when measure objects. Is there a way to have the measures provided in metric / millimeters?
The file creator controls all aspects of the file: not much you can do in the viewer except view it as created.
To change units, the file must be scaled first, unless you want to endlessly do the math: AutoCAD works with "units", a generic measurement that can be inches, mm, meters, or even lightyear and are not interchangeable with a button or switch. The file creator, or anyone able to change the file (not the viewer) must scale to redefine "units".