The path to the Build Toolkit. This will be a directory within the RTC build tools installed. Example: C:\Program Files (x86)\IBM\TeamConcertBuild\buildsystem\buildtoolkit

The path is to the Build Toolkit on the Master. If you have a distributed build setup (agents), you will also need to specify where the Build Toolkit is on the agent (assuming it's at a different path). After saving, go to the agent's configuration. In the Node properties section, add Tool locations for each of the Build Toolkits to be used on the agent. See Master/Agent Configuration for details.

If you intend to load symbolic links there is some additional setup required. Access to native libraries is required in order to create symbolic links. For more details on the setup visit Team Concert Plugin