The city government has submitted to the NGT a list of 1.9 lakh such vehicles that have been deregistered, A K Ojha, Joint Commissioner of Police (Traffic), said.
The tribunal had earlier directed to the government to stop plying of diesel vehicles more than 10 years old.
Such vehicles will be impounded under relevant provisions of the Motor Vehicles Act, 1988. Their owners will also be liable for penal action, he said.