It is always better to use individual publisher tags as opposed to this "Run Of Network" style tag. Tag sizes can be significantly greater when using an organisation tag.
Our Organisation Tag is a "Run Of Network" style tag, designed to make a rollout across a large number of publishers easier when centrally managed. This feature is available on request, so speak with your account manager if this is of interest.
Management in our UI remains the same, in that you need to set up every publisher you wish to run on and configure them accordingly
Individual publisher configs will then be bundled into this tag and loaded dynamically upon a domain match (ignoring subdomain). So be sure the domain name you entered for a publisher is correct or no ads will display.
From the management page, you can enable or disable the tag, along with the debug and beta tag toggles (these both overrule the publisher-level settings of the same name).
In addition to these, there is an "Include child organisations" toggle. When enabled, this will ensure that all child organisation publishers will also be included in this organisation tag in addition to direct children. Note: this follows the nested hierarchy down to the lowest level.
Configuring of publishers is done at the publisher level, see Publisher Tags for more information.