Airtel Xstream Fiber is one of India's two largest fibre ISPs, with strong coverage across metro and tier-2 cities. Plans are aggressive on price; real speeds on FTTH are consistent and close to advertised.
Airtel's standard router is Wi-Fi 5. Add a Wi-Fi 6 mesh, single biggest improvement on Premium and VIP plans.
Domestic peering is great; international transit congests. Common across all Indian ISPs in metros.
GPON splitters in older buildings can corrode. Ask Airtel to inspect the building distribution point.