Can you expand on what your scenario is? Retention periods are able to delete data older than the specified time perior.
retention categories are applied to data when it's archived. the retention category setting will determine how old something must be in order to be deleted by the system. the system deletion process is called expiry. this is all automated and scheduled in EV.
if you need to go in and surgically delete specific data from a search, it's going to be a manual process which is a bit more involved.