I cannot provide an answer for you 100 crore requirement. But if you want to earn extra income, there are different ways:
- Start coaching class in your subject for students in and around your locality. Investment is minimal or just your time (you already have expertise in ur subject)
- Coach students for entrance exams.
- Involve your spouse, or friend or other relative also in your business, if they have expertise, capital and knowledge of certain subjects.
- Try online tutoring - www.tutorvista.com (you get paid more for teaching foreign students in US)
- You can also do some research assignments that can earn you a Ph.D as well as get research/consulting assignments in your selected field.
If you need more information please write to me at email@example.com