“I was wondering, is there anyway to make only a specific group being able to book a specific conference room? We have mailboxes set up and is working perfectly, but we want only one specific section/unit to be able to book that conference room, is that possible?”
Yes, this can be configured on room mailboxes quite easily.
In the Properties of the room mailbox go to the Resource In-Policy Requests tab and configure selected recipients who are permitted to book the room.
When a person who is not a in that selected recipients list tries to book the room they will receive a “Declined” message similar to this.