The Bureau of Energy Efficiency, a department handled directly by India's PMO has introduced star ratings for privatly owened vehicles to determine the level of impact it has on the environment.
In my opinion, this is not a real effective policy to curb carbon emissions. Individuals are going to buy automobiles till the time they have the demand and capacity to pay for that demand.
Indian government should invest in alternative fuels and green technology; the government must also realize that there is lot of capacity in using waste fuel.
Eventually if the star rating is going to be determined by fuel efficiency, there is not going to any real favorable change in the state of the environment.