254(1): The Tribunal cannot consider new material or information which comes to the possession of the AO after passing the assessment order. The appellate procedure is designed to adjudicate matters that were originally framed in the assessment order and new material cannot be considered

Under the scheme of the Act, the order passed by the assessing officer is being contested by the assessee before Ld CIT(A) and thereafter, by both the parties before the Tribunal, if they feel aggrieved by the order passed by Ld CIT(A). After passing the assessment order, the assessing officer becomes functus officio and hence, if any material or information comes to the knowledge of the AO subsequently, then the assessing officer is required to follow the course of action provided under the Act and the Income tax Act does not provide for modification of the order that has already been passed. The appellate procedure has been designed to adjudicate the matters that were originally framed in the assessment order