All the CS5 Subscription are now migrated to CS6 CCM Subscription
By default subscription for CS6 CCM products is valid for 2 systems.
On the screen where you are getting "you have reached your activation limit" or "maximum activation count exceeded" you will get 2 button at the bottom
1. License this Software
2. Continue
Click on Continue and Enter your Adobe Id and password (on which have subscription). This will remove the subscription from previous 2 computers, after that close the AAM screen and Adobe software.
Launch the Adobe software you will get the option to license this software, Click on License this software Button and enter your Adobe ID and password (on which have subscription).
Now it should work fine and you will get deactive button higlighted in the help menu after couple of launch of the software (which means subscription is activated on the machine).