FreeForm V2 is the upgraded, faster version of digieffects FreeForm. Therefore, you must remove digieffects FreeForm from your After Effects plug-in folder, and replace it with FreeForm V2. This is because digieffects FreeForm comes bundled with CS5. Therefore it is already in your After Effects plug-in folder.
Digieffects FreeForm is no longer bundled with CS6. That means that you can simply add FreeForm V2 to your plug-in folder for CS6.