Section 6. The board shall have jurisdiction to decide appeals under the provisions of: section 42E of chapter 40; sections 2 and 14 of chapter 58; clauses Seventeenth and Twenty-second of section 5 of chapter 59; sections 7, 7A, 39, 64, 65, 65B, 73 and 81 of said chapter 59; section 2 of chapter 60A; section 14 of chapter 61B; sections 39, 67 and 68 of chapter 62C; section 2 of chapter 63; section 26 of chapter 65; section 4 of chapter 65A; any other provision of law wherein such jurisdiction is or may be expressly conferred.

Except as otherwise provided by law, no appeal to the board shall stay the collection of any tax or excise.

Whenever a board of assessors, before whom an application in writing for the abatement of a tax is pending, fails to act upon said application, except with the written consent of the applicant, prior to the expiration of three months from the date of filing of such application, it shall then be deemed to be denied, and the taxpayer shall have the right, at any time within three months thereafter, to take any appeal from such denial to which he may be entitled by law, in the same manner as though the board of assessors had in fact refused to grant the abatement applied for. After the expiration of said three months from the date of filing such application, the board of assessors shall have no further authority to act upon said application; provided, however, that during the period allowed for the taking of an appeal, including instances where the application for abatement has been denied, the assessors may, by agreement with the applicant, abate the tax in whole or in part in final settlement of said application, and shall also have the authority granted to them by section 7 to abate, in whole or in part, any tax as to which an appeal has been seasonably taken.

Whenever the commissioner of revenue, before whom an application in writing for the abatement of tax is or shall be pending, fails to act upon said application prior to the expiration of six months from the date of filing of the same, it shall then be deemed to be denied unless the applicant shall have filed with the commissioner, prior to such expiration, his written consent to the failure of the commissioner to act on said application within said six months' period. Said consent may be withdrawn by the applicant at any time, in which event said application, unless previously acted on by the commissioner, shall be deemed to be denied at the expiration of said six months' period or on the date of such withdrawal, whichever is later. The applicant, at any time within six months from the date on which any such application shall be so deemed to be denied by the commissioner, shall have the right to take any appeal from such denial to which he may be entitled by law in the same manner as though the commissioner had in fact refused to grant the abatement applied for. The commissioner shall have authority to act on any application after the date of any denial if the applicant has not seasonably taken an appeal from such denial. During the period allowed for the taking of an appeal, the commissioner may, by agreement with the applicant, abate the tax in whole or in part in final settlement of said application subject to the provisions of section 37A or 37C of chapter 62C.