Support for Server 2012 started with RU2 and above so yes it's supported. RU3 just came out last week so I would suggest starting with that.
Upgrading or migrating to Symantec Endpoint Protection 12.1.3 (RU3)
http://www.symantec.com/docs/TECH206823
System Requirements for Symantec Endpoint Protection, Enterprise and Small Business Editions, and Network Access Control 12.1.2 and 12.1.3
http://www.symantec.com/docs/TECH195325