How you can start earning with Zero Investment ?

Take a dealership of any Telecom giants.

1. For example BSNL pays you 3.4% Commision after deducting Tax.
    They will pay around 4.125 % if we do not fall in taxable limit . So to get that we need to file
     Income tax return. 

2.Higher commission will be available if you are doing MNP ( Mobile number portability)

Added Advantage
Once you have enough customers you can use your cash back from well known wallets like Paytm, Freecharge etc