Sharepoint 2013 SP1 Support in Windows Server 2012 R2

Before the release of Microsoft SharePoint Server 2013 Service Pack 1 (SP1), Microsoft did not support the installation of SharePoint Server 2013 in a Windows Server 2012 R2-based environment. However, with the release of SharePoint Server 2013 SP1, this configuration is supported in Windows Server 2012 R2. You can now download SharePoint Server 2013 SP1 from the Microsoft Developer Network (MSDN), the Volume Licensing Service Center (VLSC), and the Microsoft Partner Network (MPN).

More Info :

http://support.microsoft.com/kb/2891274

Before SP 2013 Sp1

http://iouchkov.wordpress.com/2013/10/19/how-to-install-sharepoint-2013-on-windows-server-2012-r2/