law: Railways Act, 1989
  45. Revision of decisions given by the Tribunal. 
  Where a railway administration considers that since the date of
  
  decision by the Tribunal, there has been a material change in the circumstances
  
  on which it was based, it may, after the expiry of one year from such date,
  
  make an application to the Tribunal and the Tribunal may, after making such
  
  inquiry as it considers necessary, vary or revoke the decision.