To buy USDT from the INR balance kindly follow the below steps.
1) Visit USDT/INR market - https://wazirx.com/exchange/USDT-INR
2) Click on the Buy option
3) Enter the amount and rate at which you want to buy USDT. For instant execution of your order, you can select the Lowest Price option and place the order
4) Your Order will get executed as per the order matching process and you will receive USDT in your funds