S. 263 : Commissioner-Revision of orders prejudicial to revenue-limited scrutiny-Optionally convertible cumulative preference shares at premium-Circulars would not be applicable vis-a-vis power under section 263-Discretion exercised by Commissioner under section 263 could not be restricted vis-a-vis limited scrutiny under CASS-Tribunal’s order needed to be re-examined as Tribunal either had substituted or expanded reasoning of Commissioner, thus, matter was to be remitted to Tribunal for reconsideration afresh. [S. 56(2)(viib), 68, 260A, Rule 11UA]