I want to book a return flight to India but on my return flight, my wife will be accompanying me. How do you do this on air-travel websites? Because return tickets are extremely cheap compared to one way tickets.
Given that you have different itineraries you will need two different bookings and there is no easy way to link the two bookings together. Your best bet is to book early with the same airlines and reserve seats together while there are still plenty of open spots.
These days, one way tickets are typically NOT more expensive than round trip tickets. For example FRA-DEL in mid Feb is around $600 for a round trip and around $450 for a one way.