if you are fine with airtel at 100mbps, just get it downgraded to 40mbps for a few days. here in gurgaon, their 40mbps give speeds over 100mbps all the time for some reason. and i think this happens in many other cities as well. others might be able to confirm.
this is airtel 40mbps on pi4 ON VPN.

Source
this is airtel 40mbps on pi4 ON VPN.

Source