law: 20. Budget.-
  (1) The Board shall, by such date in each year as may be specified by the Central Government, submit to it for approval a budget for the next financial year in the form specified by it, showing the estimated receipts and expenditure, and the sums which would be required from the Central Government during that financial year.
  (2) If any sum granted by the Central Government remains wholly or partly unspent in any financial year, the unspent sum may be carried forward to the next financial year and taken into account in determining the sum to be provided by the Central Government for that year.
  (3) Subject to the provisions of sub-section (4), no sum shall be expended by or on behalf of the Board, unless the expenditure is covered by provision in the budget approved by the Central Government.
  (4) Subject to such conditions and restrictions as the Central Government may think fit to impose, the Board may sanction any reappropriation from one head of expenditure to another or from a provision made for one purpose to that for another purpose.