Centre and Delhi government has also been asked not to buy any diesel vehicles for their departments.
Criticising the Delhi government's odd-even formula for vehicles to check pollution in the national capital, the green body said that such a move may not achieve the desired purpose.
"It may lead people to buy two cars," the NGT said.
The Delhi government has announced that from January 1, 2016, private vehicles with odd registration numbers will ply on Mondays, Wednesdays and Fridays, and with even numbers on Tuesdays, Thursdays and Saturdays.
Read More: Delhi announces new odd-even formula
Both odd and even number vehicles can ply on Sundays. The odd-even formula will come into force from January 1, 2016.
The Delhi government decided to run 6,000 more buses to shore up the public transport to dispel the fear of it collapsing in the face of 15-day traffic rationing.