law: Companies Act, 1956
  Sec 151    -     Index
  
  of members. 
  (1) Every company having more than fifty
  
  members shall, unless the register of members is in such a form as in itself to
  
  constitute an index, keep an index (which may be in the form of a card index)
  
  of the names of the members of the company and shall, within fourteen days
  
  after the date on which any alteration is made in the register of members, make
  
  the necessary alteration in the index.
  (2) The index shall, in respect of each
  
  member, contain a sufficient indication to enable the entries relating to that
  
  member in the register to be readily found.
  (3) The index shall, at all times, be kept at
  
  the same place as the register of members.
  (4) If default is made in complying with
  
  sub-section (1), (2) or (3), the company, and every officer of the company who
  
  is in default, shall be punishable with fine which may extend to five hundred
  
  rupees.