The link below contains archived installation files for prior Adobe products.
If you purchased retail licensed CS6 product and no longer have the installation media, you can download replacement installers from this page. You need your CS6 serial number to complete the installation. Make sure you check that your system meets the requirements for the Creative Suite 6 Products.
https://helpx.adobe.com/x-productkb/policy-pricing/cs6-product-downloads.html