law: Railways Act, 1989
  157. Altering or defacing pass or ticket. 
  If any passengers willfully alters or defaces his pass or ticket
  
  so as to render the date, number or any material portion thereof illegible, he
  
  shall be punishable with imprisonment for a term which may extend to three
  
  months, or with fine which may extend to five hundred rupees, or with both.