You do this by annotating a Git commit message with an identifier for the change request to which you want to link. You can use any Git client that can push to the registered, public Git repository, for example EGit.
By default, links are made to your primary Rational Team Concert project. You can also create links to other Rational® Team Concert projects that have been registered. A single commit can link to multiple Rational Team Concert change requests and multiple commits can link to a single change request.