Deepak, it is a great comparison but I believe you should also include the actual value of return for each card as well
This is so because the fee cost per mile is lowest for Jet Coral and highest for Amex Plat. But on absolute returns, they flip. Assuming value of each mile at 50 paise:-
Amex Plat gives me 39,800 miles worth INR 19,900 on a fee of INR 10,000. Net Return = INR 9,900
Jet Coral gives me 15,460 miles worth INR 7,730 on a fee of INR 1,250. Net Return = INR 6,480
The gap widens even further if you have a higher annual spend than INR 3lacs or if you value the miles more than 50 paise.
Focus on ratio compared to absolute returns will be optimum when you have limited supply of funds, which is not the case here.
A similar exercise will need to be done for an annual basis case.