I don't know. Haven't tried that. The thing with Millenia is that the cashback is received after 3 months, any experiment that you do, you have to wait for 3 months to see if it's working (unless someone here has done and confirms). So I play safe and load around 40k a month in wallet and use from there.
I won't be able to do this after paytm stops accepting money in wallet. I'm shifting to billpay for payments then. Only thing is, it can't be used to pay HDFC CC bill.