I have access to CC from my employer, and I installed it on my home computer. I did NOT want it to write over my copy of LR 6.14, and I didn't know it would do so. There were NO indications during installation that it would do so. Now, I'd like to revert back to LR 6.14, if possible. Preferably, I'd like to keep BOTH versions installed, but not sure that's an option.
Did you install the Lightroom cloud version or Lightroom Classic? I don't believe either application instal would replace your copy of Lightroom 6, and I know for certain neither would replace your Lightroom 6 catalog file.