§ 86. Reduction of rentals in housing company projects. If in any calendar or fiscal year the gross receipts of any housing company should exceed the payments or charges specified in section eighty-five, the sums necessary to pay distributions or interest accrued or unpaid on any shares, income debentures or other capital, and the authorized transfer to surplus, the balance shall, unless the board of directors, the partners or the trustees, as the case may be, with the approval of the commissioner shall deem such balance too small for the purpose, be applied to the reduction of rentals, for such year or years as the commissioner may specify, or to the further reduction of any mortgage indebtedness, or both, as the commissioner may determine.