THE RAILWAYS ACT, 1989 – Chapter XV – Section 157

157. Altering or Defacing Pass or Ticket
If any passenger 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.

Forward reference⇒ Section 158