It is admirable that you are ambitious but starting a business because you want to earn money and be independent are the wrong reasons. You have to base it on what the public wants, not what you want.
A new business will survive if you can find an area where a demand isn't being met or is being met very inefficiently. You will need to develop a high degree of expertise in that area.
If you can think of products a lot of people in Mumbai are willing to buy but have trouble getting, supplying those goods or services will be your best opportunity for a new business.