law: Railways Act, 1989
  41. Burden of proof, etc.
  In the case of any complaint under clause (a) of section 36,- 
  (a) whenever it is shown that a railway administration charges
  
  one trader or class of traders or the traders in any local area, lower rates
  
  for the same or similar goods or lower charges for the same or similar services
  
  than it charges to other traders in any other local area, the burden of
  
  providing that such lower rate or charge does not amount to an undue
  
  preference, shall lie on the railway administration; 
  (b) in deciding whether a lower rate or charge does not amount
  
  to an undue preference, the Tribunal may, in addition to any other
  
  considerations affecting the case, take into consideration whether such lower
  
  rate or charge is necessary in the interests of the public.