Authorities have lifted Stage IV restrictions under the Graded Response Action Plan (GRAP) in Delhi-NCR due to improved air quality, with the AQI dropping to 'Poor' levels. This means bans on certain vehicles and construction activities are no longer in effect. However, GRAP Stages I, II, and III remain active, continuing to restrict BS3 petrol and BS4 diesel vehicles. BS4 petrol vehicles are permitted to operate in Delhi-NCR, provided they have a valid PUC certificate, and entry restrictions for out-of-state BS4 petrol vehicles have also been lifted.