Does Backup Exec or System Recovery available for Ubuntu Linux?
Couldn't find Ubuntu in SSR2011 compatibility list.
BE2012 supports below versions of Ubuntu. (couldn't find SCL url as support site is down)
BE15 Useful Links
EV 11 New Features
If you mean can Backup Exec be installed on Ubuntu? No!
Can you backup data on a Ubuntu machine using Backup Exec? Yes, by using an Remote Agent for Linux (supported versions mentioned by AmolZeroCool and as per the Backup Exec 2012 SCL)
Can you perform DR of Ubuntu using Backup Exec 2012? No, you can backup/restore flat files from/to your Ubuntu box.
Does Symantec System Recovery support Ubuntu? Not yet! Here's the link for SSR 2011 Compatibility List - http://www.symantec.com/docs/TECH157280 (Page -36)