Require REST URI for getting release and user story details
Accepted answer
If you are looking for "Planned For" value, you can try
https://server:port/ccm/rpt/repository/workitem?fields=workitem/workItem[projectArea/name='JKE Banking (Change Management)']/target/name
To get the work items planned for a particular release, you can use it in filter
https://server:port/ccm/rpt/repository/workitem?fields=workitem/workItem[target/name='2.0']/(id|summary)
will return ID and summary of all work items planned for 2.0 release
To access individual work item, you can use the work item ID as filter
https://server:port/ccm/rpt/repository/workitem?fields=workitem/workItem[id=123]/(description|summary|severity|state)
or
https://server:port/ccm/rpt/repository/workitem?fields=workitem/workItem[id=123]//
will give work item details for WI #123