Hello,
I would recommend you to upgrade Symantec Endpoint Protection Manager and the SEP clients to 11.0.6005 and then to 11.0.6300.
I would like you to read and Check this Symantec Thread before you take any decision:
https://www-secure.symantec.com/connect/forums/sepm-upgrade-110420275-1106-mp3
&
About Maintaining Consistency of Software Versions throughout a SEP 11 Organization
Again, its your decision...
Now, Since you are carrying Older version 11.0.5002
We recommend you to upgrade the Symantec Endpoint Protection Manager and all clients to Latest version.
You can download the latest software from Fileconnect.
https://fileconnect.symantec.com/
Since you are carrying older version than 11.0.6005 (RU6a), there would be 2 upgrades you will have to go through. Please check the steps below:
1) From Symantec Endpoint Protection 11.0.5002 to Symantec Endpoint Protection 11.0.6005 (RU6a)
http://www.symantec.com/business/support/index?page=content&id=TECH131653
2) From Symantec Endpoint Protection 11.0.6005 (RU6a) to Symantec Endpoint Protection 11.0.6300 (RU6 MP3)
http://www.symantec.com/business/support/index?page=content&id=TECH155655
Reason for Migration:---> check the Symantec Article below:
Release notes for Symantec Endpoint Protection 11.0.x and Symantec Network Access Control 11.0.x
Yes, for Automatic Upgrades of all SEP 11.0.2000 clients, you can follow the Auupgrade feature from SEPM...
Upgrading clients by using AutoUpgrade