From kalilinuxtutorials.com
Grouper2 is a tool to find vulnerabilities in AD group policy. It is a tool for pentesters to help find security-related misconfigurations in Active Directory Group Policy.
It might also be useful for other people doing other stuff, but it is explicitly NOT meant to be an audit tool. If you want to check your policy configs against some particular standard, you probably want Microsoft’s Security and Compliance Toolkit, not Grouper or Grouper2.