(c)where any order referred to in this sub-section and passed by the Assessing Officer 92[or the Transfer Pricing Officer, as the case may be,] had been the subject matter of any appeal filed on or before or after the 1st day of June, 1988, the powers of the* Principal Commissioner or Commissioner under this sub-section shall extend and shall be deemed always to have extended to such matters as had not been considered and decided in such appeal.