Download Microsoft Windows Server 2012 R2 LANGUAGE PACK RTM X64 ENGLISH
Pretty self-explanatory leak here from the Russian badasses at WZT.
This is the language pack component for server2012r2 so that you can add a language to an existing server2012r2 install.
As usual, it translates most everything, but is still slightly inferior to a fully-localized RTM.
These are not compatible with Windows 8.1