I think we should take the largest 10 cities of India and make them special Union Territories- Mumbai, Delhi(already separate), Kolkata, Chennai, Bangalore, Hyderabad, Ahmedabad, Surat, Pune and Kanpur.
This will have the following benefits:
- Make the states focus on developments of smaller cities and towns and rural development as they lose the big cities
- Reduce the kind of jingoism coming from Raj Thackeray in Mumbai as these cities become truly cosmopolitan
- Improve overall economic development as it spreads across a bigger region