Yes Lync Server 2013 is supported on Windows Server 2012 R2. You must have installed Lync 2013 CU 3 from October 2013.
Please refer: http://technet.microsoft.com/en-us/library/gg398588.aspx
- Windows Server 2008 R2 SP1 or latest service pack
- Windows Server 2012
- Windows Server 2012 R2
The Active Directory Servers are also supported with Windows Server 2012 R2 AD.
Please feel free to deploy 2012 R2 AD.
Beside this, Exchange 2013 will only run on W2k12 R2 Servers, if SP1 is used for installation.
If you encounter errors in the event log, ID 32402 and ID 61045 the is work around to solve this issue.
If you ask for an server in-place upgrade from Windows Server 2012 to 2012 R2. Microsoft did not stated any information regarding this. Windows in-place upgrade itself is fully supported, without any information regading the application.
Author: Thomas Pött Managing Consultant Microsoft UC