I think the best card for online shopping will be from SBI. The card is SBI Simply Click Card.
1.25% cashback on all online shopping
2.5% cashback on shopping done at amazon, foodpanda, ola, lenskart etc
Rs. 4000 worth amazon gift voucher on reaching Rs. 200,000 per annum spends
Rs. 500 amazon joining gift voucher
To get more benefits, you can also search for klippd on google.
klippd helps user get extra cash backs to the tune of 21%. This cashback is over and above the existing discounts and offers.
You can apply for the card here