CS6 and earlier programs have not been tested and will not be updated to run on Mac El Capitan
-which means that you try to use CS6 and earlier at YOUR risk of having problems
-you may get CS6 and earlier programs to install and run, or you may not (some do, some don't)
This is about a different program, but it MAY help
I can only recommend to upgrade to a CC subscription with El Capitan.