I’m always trying to make sense of TCC versions and found this article on MOS that addresses it SD6004 – TCC Version (Doc ID 1047569.1)
There are three versions to keep track of for TCC using clients: zone, feature pack and TCC.
The zone version is the version of Taleo Recruiting, Performance and/or Onboarding. It isn’t dependent on any other product’s version.
The feature pack contains the data dictionary. Its version is linked to a Taleo zone Service Pack. Any new object or feature introduced in a zone version will be made available to TCC in the feature pack of the same version. Existing touchpoints don’t need to be upgraded to the latest feature pack, but any new or modified integration should use the feature pack for the current Taleo zone version. If the touchpoint in question is a net change import, then a net change setup must be done before resuming the imports. Note that if there are no new features added to TCC, then there will be no feature pack released for that SP.
Finally, the TCC version is only related to the TCC software installed locally at the client site. Any TCC version should be able to use any feature pack, so upgrading is not necessary. On the other hand upgrading TCC will not have any functional impact on any integration except net change, so keeping up to date is a best practice. For net change imports, a net change setup may be required and is always recommended after installing a new TCC version. Read the release notes to see if the net change setup is required or not.