Power to reopen proceedings permits the Settlement Commission, with applicant's concurrence, to reopen completed tax proceedings for proper disposal. The Settlement Commission may, for proper disposal of a pending settlement case and for recorded reasons, reopen any connected proceeding previously completed under the Act with the concurrence of the applicant and pass any order as if the settlement application had covered that proceeding; reopening is subject to a nine-year time limit from the end of the relevant assessment year and is barred for applications made on or after the statutory amendment date.