Late fee waiver for delayed GSTR-3B filing provides conditional relief for registered persons filing within specified extended windows. The notification prescribes conditional waivers of late fee for delayed furnishing of FORM GSTR-3B by setting per-day minima and total-waiver thresholds, and by defining specific filing windows and eligibility criteria based on aggregate turnover and principal place of business. Where returns are filed within the enumerated extended windows, late fee is capped or waived-often fully waived when the central tax payable is nil-subject to the tables and provisos that differentiate relief by turnover bands, locations and tax periods.