Hi,
Q. Can we directly upgrade from SEPM 11 RU6 MP3 to SEPM 12.1 RU2 ?
--> You can upgrade from SEPM 11 RU6 MP3 to SEP 12.1 RU2
You should check thir article prior to upgrade
SEP 11.x to SEP 12.1 Upgrade process graphical overview
https://www-secure.symantec.com/connect/articles/sep-11x-sep-121-upgrade-process-graphical-overview
Supported upgrade paths to Symantec Endpoint Protection Manager 12.1 from Symantec Endpoint Protection Manager 11.x
http://www.symantec.com/docs/TECH192779
Supported upgrade paths for the Symantec Endpoint Protection client
http://www.symantec.com/docs/HOWTO81070
In case you see SEP 12.1 RU2 available for download then it might be in English Edition only.
For local languages you might have to wait for few more days. (Probably till 30th Nov'12)
For suites you might have to wait till December'12.