Section 21(4)(a) in The M.P. Prakoshtha Swamitva Adhiniyam, 2000
(a)enabling the board to retain certain areas of the building for commercial purposes and to grant lease of the areas so retained and to apply the proceeds of such lease for the reduction of the common expenses for maintaining the building and the common areas and facilities and, if any, surplus is left after meeting such expenses to distribute such surplus to the apartment owners as income;