Hi,
Package manager does help when you want to move users & groups privileges from one instance to another which is a different case.
In order to solve the above problem, we are still going to use package manager. Follow the steps below:
Create a package and put all the users & their groups.
Exclude few users & groups :
admin & administrative anonymous (not necessary but good to keep it excluded)
If same user & group are found in both environments; delete from AEM 6 instance before installing 5.6 user package. You should ignore admin & anonymous here too
Install it
To verify your accounts, login with any of your group. Also you can verify logged-in user’s privileges.
Note :
This solution is tested and proven in one of our applications. However, if you still find any issue, leave a comment, we will try to help you.
Source Link:- http://www.tothenew.com/blog/users-migration-from-cq5-6-to-aem-6-06-1/
~kautuk
Kautuk Sahni