To a remote ref crew. Avoid the on the court refs from having to set up their tiny little TV's and headsets (it's laughable that we can have a much better picture of the play than they do and yet they are making the call).
Review team gets 60-90 seconds to make a call and let the on the court refs know, otherwise, play stands as called.
Reviews are only eligible on coaches' challenges and potential flagrant calls. All other calls are made immediately on the floor by the ref.