What exactly do you mean by ''move''? Move requirements from one folder to another? Would the users still be allowed to create, delete, and/or modify requirements?

One way you can change group permissions in a project if you have Project Administrator access and can get to Tools > Customize... and in there get to Groups And Permissions. You are not allowed to change the permissions of the default groups defined for ALM (Developer, Project Manager, QATester, TDAdmin, Viewer). If the users belong to one of these groups you'll need to create a custom group and move the users to that group. The capability for managing group permissions in this area may or may not fulfill your needs.

Another way to manage group permissions is to modify the workflow code. This is also accessible through Tools > Customize... in the Workflow module. Once you identify which workflow is executed when a user tries to ''move'' a requirement, you can insert custom code into that workflow to block the capability for users belonging to the specified group.

Both of these features are addressed the the Administrator Guide.