Is the below Oracle support document applicable for Windows 2012 R2 OS & Windows 2012 OS or how?
Yes, correct. It is clearly mentioned on the document.
Oracle Hyperion Financial Close Management, Tax Governance, and Account Reconciliations Module release 188.8.131.52 are dependent on Oracle SOA. Oracle SOA has not been certified on Windows 2012 R2. However, Oracle Support will assist customers running Financial Close Management, Tax Governance or Account Reconciliations Module release 184.108.40.206 deployed to Windows Server 2012 R2 by providing support for issues that occur on a certified platform. If a problem is a known Financial Close Management, Tax Governance or Account Reconciliations Module issue, Oracle support will recommend the appropriate solution on a certified platform. If that solution does not work in Windows Server 2012 R2, the customer will be referred to Microsoft for support. If Microsoft cannot resolve, the customer will have to establish its own workaround or redeploy to a certified platform. When the customer can demonstrate that the Financial Close Management, Tax Governance, or Account Reconciliations Module solution does not work when running on a certified platform, Oracle will resume support, including logging a bug with Oracle Development for investigation if required.
Oracle recommends customers that have not already upgraded to Windows 2012 R12 remain on a certified platform.