Hello there .
This question has all it's answer in your interest .
I would say if gaming (game devolvement) excites you and that's what you love to do ,then there is nothing better than it .
Whereas, IIT is more of a professional course . Ofcourse it gives you some good placement  security ,if you manage to crack a good college . And yes, the pay can be at tines higher than gaming .
But see it like this ,if you're passionate about gaming ,then nothing can stop you from getting succeed here .
So it would be foolish to go for the one that's not your interest .
Last choice would be yours . Choose the one that makes you happy .

Goodluck.