I would say Mumbai!
No doubt there are plenty of push factors but yes some pull factors of investing in Mumbai are,
1) Commercial Heart of India
2) Financial Capital of India
3) Bollywood Capital of India
4) Importance of Face to Face Meetings
5) Talent Pool
6) Inertia Affect
One of the major reasons is the talent pool. If you are working in finance or Bollywood or at a corporate, you want to come to Mumbai because that is where the best & high paying jobs are in your dream field.
If you are working in finance or Bollywood or at a corporate, you want to come to Mumbai because that is where the best & high paying jobs are in your dream field. So you come to Mumbai, land a job, start a family, put your kids in school and before you know it you’re a Mumbaikar.
It’s more likely that if you make any changes it will be to move to another company within Mumbai than changing Cities. Those companies that don’t have a location in Mumbai thus risk not having access to the best talent in India now and later. In turn, an inertia effect occurs where Companies have to stay in Mumbai because that is where the talent is and individuals have to come to Mumbai for the best jobs in their field. To be fair, this is not a Mumbai phenomenon but applicable to all major Alpha Cities: New York City, San Francisco Bay/Silicon Valley, London, Hong Kong, Tokyo, etc.
Simply put, India is growing faster than any other major economy and Mumbai is its commercial capital. For the long term, I think buying commercial property in Mumbai whether it be Office space or Retail space is an obvious decision.