Yes it is released in Enterprises version.
New version 12.1 ru5 is release in English Version and avaialble in file connect
New Platforms: Windows 8.1.x, Windows Server 2012 R2.x and Mac OS X 10.10
What’s New
As part of the upgrade to Symantec Endpoint Protection Manager (SEPM) 12.1 RU5, all content converts from full definitions to delta definitions.
All the document available in below article shared by Chetan
English versions of Symantec Endpoint Protection 12.1.5337.5000 (RU5) is now available
https://www-secure.symantec.com/connect/blogs/symantec-has-released-new-version-symantec-endpoint-protection