Which credit card is the best

Yaar bc search function use karlo. 1000000 threads hai CC pe. Uspe lelo gyaan.

What are your major spend categories? Do you like simple cashback or are more into travel?

Amex MRCC. Bonus Membership rewards for pretty much anything, and they never expire. Plus the prestige of owning one is pretty awesome.

Flip side, physical acceptance outside of tier 1 cities will be challenging.

I think HDFC Infinia is the best of what's left. Else Axis Magnus (Don't use)

Diners black LTF if you can get!

Don't use one. It's a trap.

I have found the hsbc cashback back to be extremely rewarding with 10% cashback

I've been using Amex MRCC credit card for most of my spending which are around ₹20k in most of the months. You can redeem their Membership Reward (MR) points to airlines miles, gift vouchers etc at a very good rate (~10%). Feel free to reach out on WhatsApp to know more details regarding it: 9911626956. 

Amex referral (First year free for you + 2000 added bonus points on spends of ₹5000): https://americanexpress.com/en-in/referral/hARShGuqru?XL=MNANS