Held that the Assessing Officer not following the mandatory provisions of law would render the assessment order erroneous and amenable to the jurisdiction under section 263 of the Act. The contention of the assessee that it was agricultural land and did not come within the purview of section 56(2)(vii)(b) was not sustainable because whether the lands in question were agricultural was not pleaded either before the Assessing Officer or before the Principal Commissioner, the assessee himself had admitted the applicability of the provisions of section 56(2)(vii)(b) by submitting the valuation report, and an issue concluded against the assessee in the original assessment proceedings could not be agitated in revision proceedings.  Revision is justified.(AY.2015-16)