If authorities initially treat land issuance as irregular, not void ab initio, a five-year limitation applies for reopening the caseUttar Pradesh Zamindari Abolition and Land Reforms Act, 1950 — Section 198(4) —The appellant, issued a patta in 1991, faced cancellation in 2000 under Section 198(4) — The cancellation was upheld by authorities — The appellant argued the show cause notice was issued after the 5-year limitation period under Section 198(6)(b), rendering t