Dream 11 is a great platform to earn money using your knowledge about a sport. Currently they provide three sports football, cricket and kabaddi.
Here you can use your knowledge, your ability to predict to earn hard cash. I am using this app for a year now and I have earned about 500 rupees till now.
It is a great way to earn money online legally. You have to pay 31 percent income tax on your earning above 10000 rupees.
But it is a risky game. All of your predictions will not be true everyrime. Be patient and collect more information about teams and players before putting your money on them.
You also earn 100 rupees by inviting your friends. As they play you will earn money. Happy earning. Cheers!