While performing an Offline installation of SP 2013 with SP1 on Server 2012 R2 it errored out stating that it couldn't download WCF Data Services 5.6 which I already had added to the prereq folder. I modified line 664 in AutoSPInstallerFunctions.ps1
/WCFDataServices56:`"$env:SPbits\PrerequisiteInstallerFiles\WcfDataServices56.exe`"
Comments: ** Comment from web user: ashembers **
/WCFDataServices56:`"$env:SPbits\PrerequisiteInstallerFiles\WcfDataServices56.exe`"
Comments: ** Comment from web user: ashembers **
I am pretty sure that SharePoint 2013 can only be installed on Server 2012 & not 2012R2. We ran into that problem a couple months ago, so I would hope that was not the case still, but bet that it is.