law: 9. Powers of Commissioner.
  Subject to the control of the Central Government, the Commissioner, whenever it is necessary so to do for any of the purposes of this Act, may
  (a) enter upon and inspect the metro railway or any rolling stock used thereon and its other installations;
  (b) by order in writing addressed to the metro railway administration, require the attendance before him of metro railway official and to require answers or returns to such inquiries as he thinks fit to make from such metro railway official or from the metro railway administration; and
  (c) require the production of any book, document or material object belonging to or in the possession or control of any metro railway administration which appears to him to be necessary to inspect.