Hello and welcome.
Because Adobe CS6 was released back in 2012, unfortunately it isn't officially compatible with the last few versions of OS X. Some have reported that there are a few apps that work, but there are more problems than it would be worth.
The current Creative Cloud does work beautifully, however many don't like the subscription-based licensing model.
Do you use all of the apps in CS6, or just some of them? There are some excellent substitutes available for a lot less money.
C
I'm running Creative Suite 4 Design Standard (Photoshop, Illustrator, InDesign, Acrobat Pro) on my MacBook with Sierra (10.12.6) installed, and they all run beautifully with the exception of Illustrator, so I back-stepped to Illustrator CS 3, and now it runs fine.
I also have CS 3 Production Premium (Premiere, etc.) and all those apps run quite well, again under Sierra.
And definitely count me in as being one of those people who don't like subscription-based licensing models. The only words I can find to accurately describe my disdain for renting software could not only never be published here, but would probably getting me banned from this site until a couple of months after Rapture!
I will disagree about there being "excellent substitutes" available. I've tried most of them (GIMP, InkScape, Scribus and many others). Anyone who's become accustomed to Adobe software will hate the interfaces, the learning curves and the utter lack of features.