When managing a Windows Server 2012 R2 environment without direct internet access, you cannot use the standard "Add a language" feature in the Control Panel. Instead, you must perform an offline installation using a Language Pack ISO or a standalone www.gotoadm.ru 1. Where to Download Language Packs Offline
For volume license customers, the original ISO is available as: windows server 2012 r2 language pack offline download
For those without portal access, community-maintained archives such as the Internet Archive When managing a Windows Server 2012 R2 environment