The latest available version of Symantec Endpoint Protection is 11.0 Release Update 6a
The version number for that build is: 11.0.6005.562

The release notes detailing fixes in this build are located here: http://service1.symantec.com/support/ent-security.nsf/854fa02b4f5013678825731a007d06af/2c62c4ee0e697aae882573b000034ded?OpenDocument
Migration instructions are located here: http://service1.symantec.com/support/ent-security.nsf/854fa02b4f5013678825731a007d06af/6f5427dfdd4a0cc18825770400611b5a?OpenDocument

RU6a is available to download from the following locations: 

Client Only patches: http://www.symantec.com/business/support/downloads.jsp?pid=54619
Symantec FileConnect: https://fileconnect.symantec.com (login with serial number required)
Symantec BCS: https://www-secure.symantec.com/platinum/en/products/all/sep_11.0/

RU6a is currently available in the following languages: English

RU5 is currently available in the following languages:  French, German, Italian, Spanish, Russian, Brazilian Portuguese, Polish, Czech, Japanese, Korean, Simplfied Chinese, Traditional Chinese