S. 264: Commissioner-Revision of other orders-Rectification of mistake-Long term capital gains-Time-Limit-Sale of flat inherited-Indexed cost of improvement-Omission of claim of deduction of Indexed renovation expenses in return of income-Rectification application is rejected on the ground that new claim was not raised earlier-Claim was accepted in other co-owners-Matter remanded for de novo consideration. [S. 45, 48, 50(C)(2), 143(3), 154, Art. 226]c