Which HDFC debit card to get?

I recently moved to HDFC preferred banking from classic. Been holding a rupay platinum debit card till now but preferred (and even classic) banking offers free platinum card for customers. 

Reason for holding rupay: Got it when I had a normal savings account, as annual charges were lowest, and didn’t switch recently because of Amazon add money offer on fridays.

Should I keep holding the rupay card (will there be any annual charges on this?) ? 

Or switch to millenia (will this count as free platinum dc?) or easyshop platinum dc ?

If I go for millenia, whats the max cb I can earn in a month and how?

For easyshop am I correct to assume that cc payment will give 1% cb (so I have to pay 75k bills every month to fully utilize that?). I dont wanna use dc for usual online purchases as I have better credit cards for that