New York Consolidated Laws, Criminal Procedure Law - CPL § 190.10 Grand jury;  for what courts drawn

The appellate division of each judicial department shall adopt rules governing the number and the terms for which grand juries shall be drawn and impaneled by the superior courts within its department;  provided, however, that a grand jury may be drawn and impaneled for any extraordinary term of the supreme court upon the order of a justice assigned to hold such term.