Your Kotak FASTag wallet can be set for an Auto-Recharge with a pre-defined amount from your Kotak Bank Savings Account only.
Steps to enable the Auto-Recharge:
1) Log in to Kotak FASTag Portal - https://fastag.kotak.com/ with your registered mobile number and password
2) Go to Auto Recharge section (Left Menu) and toggle (Right) to Enable
3) Enter the amount for Auto Recharge
4) Click on Set Auto Recharge and confirm with OTP sent to your registered mobile number
5) Select the Kotak Bank Account from which the Recharge amount should be Debited and Confirm.
6) Auto-Recharge would be set successfully