Most large cities in India are extremely polluted, and the smaller ones aren't necessarily any better. I have been all over India, over 15 states and union territories. Even the cleanest Indian cities I have been to (e.g. Chandigarh and Puducherry) are filthier than a regular city in other countries I've visited. It will take massive overhaul of garbage disposal and recycling infrastructure, as well as a massive cultural shift in how we treat our public spaces to overcome our enormous pollution problem.