law: 56. Refund of taxes collected in excess.-
  The liability of the State of Bombay to refund any tax or duty on property, including land revenue, collected in excess shall be the liability of the State in which the property is situated, and the liability of the State of Bombay to refund any other tax or duty collected in excess shall be the liability of the State in whose territories the place of assessment of that tax or duty is included:
  Provided that the liability to refund any amount after the appointed day on account of any excess collected in respect of any tax accruing during the period between the 1st day of January, 1960, and the 30th day of April, 1960 (both days inclusive) under the Central Sales Tax Act, 1956 (74 of 1956) or the Bombay Sales Tax Act, 1959 (Bom. Act LI of 1959), shall be shared between the two States of Maharashtra and Gujarat according to the population ratio.