Adobe Premiere Pro CS6 is a "legacy" product that reached its end-of-life status years ago. Because of this, the way you activate it has changed significantly: Official Support Ended
: Many of the original activation servers for CS6 have been retired. Even with a legitimate historical serial number, users often encounter "Activation Limit Reached" or "Server Unavailable" errors. How to access Premiere Pro today serial number adobe premiere pro cs6 family
However, if you're looking for a way to obtain a legitimate copy of Adobe Premiere Pro CS6, here are some options: Adobe Premiere Pro CS6 is a "legacy" product