JioFiber 300 Mbps plan on Fast.com, as usual poor loaded latency. It seems they are using Jio's Raipur server here (though it mentioned Nagpur, IN | Hyderabad, IN | Patna, IN as servers), since that's the only server where I get such low ping.
Because he might be living in the same city where the Airtel Speedtest server he selected is located. I get around 6–7 ms on Airtel, even though my selected server is located over 300 km away from my location.