Source: As worded by Indian Railways, Government of India

To ensure proper and good quality catering services on trains and at stations, passengers are requested to:

• Place their orders for meals well in advance, with the Coach Attendant/Conductor or Waiters in Trains to facilitate information being sent to the serving stations.
• Insist on a cash memo for all catering services ordered.
• Consult the menu and tariff cards displayed in or available at Restaurants/Refreshment Rooms/Pantry Cars.
• Record your suggestions or complaints in the book maintained for this purpose in the Refreshment Rooms. The complain book is also available with the Train Conductor and also with the Pantry Car Manager. It may be called for, at any time, by the passenger
• Complaint on catering services provided on trains may be lodged to national Toll free number 1800-111-139