I will answer this question 2 parts
Everything will be subject to eligibility
1. Reward points redemption
You can get axis bank atlas credit card with a joining and annual fee of Rs 5000
But you will get edge miles on payment of the fees which can be transferred into various airlines points for international travel with multiple partner airlines.
You get spends based milestones for edge miles too which can be redeemed for airline points giving you further benefits.
It is one of the best credit cards you can get for international travel.
2. Co-branded credit cards
A) standard chartered easemytrip cc
This credit card has a joining and annual fee of 350.
It gives you 10% off on your airline bookings via easemytrip app. There are also offers for domestic bookings and train bookings that you can avail.
B) Ixigo AU credit card
This is a card that I personally use.
It is having lifetime free offer currently.
It gives you 10 percent off on airline bookings through ixigo app with a cap of 2 bookings per month.
You also get 10 percent off for railway booking bus booking etc.
You also earn reward points which can be converted to club vistara CV points which can also be redeemed for bookings made directly on club vistara later.
One additional benefits that this has is you get 8 airport and 8 railway lounge access free for a year, i.e. 2 each per quarter.
And 1 international lounge access complimentary through on demand priority pass.
And 0 forex charges which is beneficial for international travel
The card is also currently available in a Rupay variant to help UPI linking.
Overall, I still feel Axis atlas will give you the best reward rate and international flight bookings but that benefit is spend based and you can redeem it later, whereas Ixigo AU or standard chartered easemytrip will give you upfront benefit of 10 percent.
I hope this helps and you can choose which will be more beneficial for you.