Booking OCI holder senior citizen on AI biz class single PNR via EWR - BOM - AMD (AI 144 -> AI 637). Will request wheelchair assist but unsure how much support will be received to facilitate customs/domestic transfer.

For baggage and customs, how does that work? Collect bags at BOM. Do they have to exit and re check in at domestic similar to how you would if separate ticket? Or is there an expedited transfer way for baggage check in and security? Senior citizen can walk but has some ankle pain and nervous about taking bags long distance.

Is the experience any different if J for the long transatlantic haul but Y for the BOM-AMD route?

Also, is a return ticket required for OCI holder, customs, or AI? Currently booking one way award and planning a 3-4 week stay pending some appointments.