Adobe Illustrator CS6 was released in April 2012 as part of the final major iteration of Adobe’s Creative Suite. It introduced the Mercury Performance System, modernized the user interface, and offered a "perpetual license" model (a one-time purchase).
CS6 is no longer sold directly by Adobe. Perpetual licenses have been replaced by monthly or annual subscription plans. Installation and Compatibility Report adobe illustrator cs6 trial
Let’s be honest: Adobe Illustrator CS6 was the peak of the "perpetual license" era. You bought it once, and it was yours. Adobe Illustrator CS6 was released in April 2012