MyBB Community Forums

hello friends, I want to restrict one of my section.Guest can view that section at home page,but shouldn't get access until they register at my site.
and when they click any forum of that section, they ll get a message telling them to register my site to access that section.
How can I do that????

Go to: ACP > Forums and Posts > Select that Forum > Edit [Options] > Permissions > Guests > Edit Permissions > and do the following;
Can view forum? [Tick]
Can view threads within forum? [Untick]