Yes, first to assign a material to your model, go to...
Tools -> Material Properties...
...and once the dialog is open go to the bottom of the dialog and select the icon labeled 'Library' (2nd from the right) and when the next dialog comes up under Category select Metals (the default), Plastics or Others, and then the Type if something other than Isotropic and then hit OK. Now select the material from the list presented, hit OK and then select your model on the screen and one more OK and you're done. Note that this material assignment will remain with the model until replaced by another Material Assignment.
OK, now if you truly want your results to be in cubic meters (m³) then you need to next go to...
Analysis -> Units -> kg-m
Now go to...
Analysis -> Mass Properties...
...and select your model. Note that on the screen it will display the volume in m³. If you wish to get a full list of all of the Mass Properties, in the dialog bar in the upper left of your screen, select the 'Info' icon (the box with the 'i' inside it).
Now if you would like to capture these same measurements as Expressions which will now update when and if you edit or update your model, select the 'Keep Measure' icon (1st icon on the left). I addition to the Expressions being created which will track the Mass Property values of your model, there was also created a Point at the Centroid of the model which will also update as the model is edited and updated in the future. Also note that if you later change the Material Assignment, you will not need to redefine the Measurement Expressions since they will automatically update based on the new specific density.
I hope this fills your needs.
John R. Baker, P.E.
Product 'Evangelist'
NX Design
Siemens PLM Software Inc.
Cypress, CA