GameTracker already provides a nice guide for this http://www.gametracker.com/games/ts3/forum.php?thread=42258

BUT...

I found this helpful info an a random site and it worked great for me to get TS3 to work in gametracker.

You need to be Server ADMIN of the TS3 Server.


Connect to your TeamSpeak 3 server, click in the TeamSpeak 3 client at the top menu bar on Permissions and open the Server Groups.

A window will open where you can setup permissions. Select now on the left side at Groups the Guest.

In the next area to the right you see the complete permissions of your server divided into categories (Global, Virtual Server, Channel, Group, ...).
Those you can fold out to see which further subcategories and permissions you can find there.

You will allow now the permission for the command from your error message.

For that take a look at the permissionoverview table (directly below) to see which categories you have to fold out and how the permission for this command is called.


PERMISSIONOVERVIEW
Command Category & Permission
serverinfo
Virtual Server
Information
View Virtual Server Info (b_virtualserver_info_view)
clientlist View List of Clients online (b_virtualserver_client_list)
channellist View List of existing Channels (b_virtualserver_channel_list)



Group
Information
channelgrouplist View List of Channel Groups (b_virtualserver_channelgroup_list)
servergrouplist View List of Server Groups (b_virtualserver_servergroup_list)



See how you go with that info, it worked for me and previously i was trying to get GT to work on my site since TS3 came out and GT supported it, lol.

Now i finally got it to work.

In version RC2 to do?

In the new TS 3 version 3.0.5 this tutorial is not compliant. Can you please update the tutorial?

EDIT: actually I just needed to mark the option to show advanced permissions under TS3 options.