HL7 DICOM broker includes in Orthanc PACS??

I would like to know how can Orthanc Dicom server interface with HIS with HL7 standard . Do we need a separate HL7 DICOM broker to interface between Orthan and HIS or Orthan has the HL7 DICOM broker plugins to send the DI Study request to the Modality which are sent by HIS.

The core of Orthanc is entirely focused on DICOM. As a consequence, it does not feature any built-in primitive for HL7.

The interface with HL7 or FHIR systems can be implemented by plugins that listen to events produced by Orthanc. An example was discussed recently in the following thread (check out point 1):

You could do the same by implementing an external script (e.g. in Python) that listens to the “/changes” URI of the REST API of Orthanc (many HL7 toolkits are available for Python):

Anybody can develop such plugins or external scripts. You are invited to give back to the Orthanc project by publishing your contributions as free and open-source software.