They claim it meets Bharat Stage III (and Euro IV) emissions standards, which is as good as any other car in India. That statement is in response to fears that as people move up from scooters/motorcycles to this car, the emissions problem would get worse.
The only thing that will get worse is the traffic problem. But that's everyone's "fault": no reason why the poor should sacrifice their safety (relative to carrying a family of 4+ on a scooter) to save commute time for others.
In Southeast Asia today there are currently 100 million motorcycles and scooters powered by two-stroke engines. Each one produces as much pollution as 50 cars. The car might be good on emissions, it might not, but this quote certainly isn't very reassuring.
The 54mpg might be good on CO2 emissions, but that isn't going to do you much good if you are one of the tens (hundreds?) of thousands who die prematurely each year from the fine particulates that get lodged in your lungs.