How to upgrade MacPro OS 10.6.8 to 10.8?
How to upgrade MacPro OS 10.6.8 to 10.8?
Mac Pro
Apple Event: May 7th at 7 am PT
How to upgrade MacPro OS 10.6.8 to 10.8?
Mac Pro
As long as your machine meets the system requirements:
http://www.apple.com/osx/specs/
You should be able to go to the App Store (since you're running 10.6.8), buy Mountain Lion, and download/install it.
FWIW: You probably have more than 2 GB RAM - 4 GB should be considered a more realistic minimum.
How to upgrade MacPro OS 10.6.8 to 10.8?