@MySql Backup & Restore
If you are referring to Commvault Client Groups then follow books online link to create the groups
Link → https://documentation.commvault.com/11.24/expert/4876_creating_client_computer_group.html
If you are referring the the Unix group then connect to mysql server as root and run id <mysql_user>
This will show the unix group which is part of the mysql user used for the backup.
Provide the Unix group name during the installation.
If you do not have this information while installing the agent the continue the installation without providing the Unix Group, however once the agent is installed connect to the Unix/Linux server and use cvpkgchg command to reset the group on the commvault install
Link → https://documentation.commvault.com/11.25/expert/1935_changing_unix_groups_and_permissions_on_unix_clients.html