One way to help social sector raise funding is to make it a part of the local economy:
- By helping people consume local products and services by non-profits, their purchases directly fund the social works. Often they cannot compete with cheaper alternatives, which could partially be addressed by ad network that optimizes for sustainability, where non-profits stand a better chance to sell.
Not all non-profits have something to sell though;
- By incentivising local businesses to collaborate and take up social initiatives in order to grow their businesses. A great way to do this would be to help them reach local customers on sustainable terms. The more social initiatives they take up (validated by local community), more customers they find.
Both could help India’s social sector raise funding as part of the economic activity (which is as mainstream as it gets). This could be key indicator for social stock exchange too. Does combination of stocks of local sustainable businesses and non-profits count as an asset?
I can see neighbourhood level indices similar to nifty and sensex, of local sustainable businesses and non-profits.
I hope this helps. 
Edit: A social platform might be of help for the social sector. I share some of the ways it can help in this grove thread.