You can always install the CS6, CC and CC2014 as you can choose all of them to be installed.
The problem must be on your computer, it is not common known.
It is not possible to find either CS6 och CC to download from the Adobe site. If someone have a link I happy to share it.
Open the CC Desktop application, click the Apps tab, scroll down to other apps group at the bottom and change the filter to Previous Versions.