law: 94. Service of notice, etc., by metro railway administration.
  Any notice or other document required or authorised by this Act to be served on any person by the metro railway administration may be served by
  (a) delivering it to the person; or
  (b) leaving it at the usual or the last known place of abode of the person; or
  (c) registered post addressed to the person at his usual or the last known place of abode.