Calculate the usable time outside the airport
Start with the airline’s required return time. Subtract terminal exit and baggage time, both road legs and a contingency for delays. A long-looking gap can shrink quickly, especially on separate tickets.
Make one site the priority
Choose the archaeological area or a shorter guided stop based on opening hours. Add the museum only if open and there is comfortable time. Do not combine a short airport stop with a boat ride and a Varanasi old-city tour.
Keep a no-excursion fallback
Share both flight numbers before booking. Agree what happens if the inbound flight is delayed or the road is slow. If the buffer becomes too tight, skip sightseeing and protect the onward flight.