The XACML registry is deployed as two features in the TESB Runtime Karaf container. There is one frontend feature: (tesb-registry-rest-atom-service) feature which installs the REST-ATOM frontend to the XACML registry. Make sure that featuresBoot in container/etc/org.apache.karaf.features.cfg includes cxf-abdera:
featuresBoot=config,ssh,management,kar,webconsole, // spring,spring-dm,cxf-abdera,cxf,camel,..
The Apache Jackrabbit XACML repository location is defined in container/etc/org.talend.esb.authorization.xacml.registry.server.cfg. The default location is container/xacmlrepository. Its Jackrabbit configuration is container/xacmlrepository/repository.xml. Here the storage type (file/database based) and repository access rights are specified.