Hello,
I guess you are talking about the Stone Web viewer. As of version 2.6 of Stone Web viewer, the rendering of DICOM-SR are not supported yet, but this is work in progress.
As far as the Orthanc DICOM server itself is concerned, it has been supporting the reception, storage, and transmission of DICOM-SR since the beginning of the project.
Regards,
Sébastien-