Thank you for using our services.
Unfortunately the Forums Module in Sitefinity 3.x does not support granular permissions. Permissions are applied on module level instead of single forum level. Granular permissions are supported in Sitefinity 4.0 and this kind of scenario will be supported in this version once we release the Forums module for Sitefinity 4.0.
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items