Dude, My parents just went back to nepal from the same route. Unfortunately they didnt get any company, or nepali to help them.  I just wanted to let you know how i arrange all this. First thing, when you go to check-in in Ohare terminal, tell them one of your parents need wheelchair in the customer service desk, no matter what, they will provide a wheel chair immediately. The person driving the wheel chair will have full responsibility to take them to the right gate/ place, more over in delhi also, there will be another person waiting in the door of plane with wheel chair to take your parents out (wheel chair service is totally free and seat/seat service, meaning they will take from the seat of one plane to the seat of another and finally to the parking lot of the destination). when they reach delhi, your parents can at least speak and understand hindi, instruct your parents to tell the wheel chair driver to take them to overnight stay place. There is a place in delhi airport where they can comfortably spend night , but they have to pay their stay in hourly basis (not a hotel, it is in the terminal transit area, with single bed size couch where one can easily sleep, it was almost 300 IRC for their 12 hours stay).  The wheel chair driver will himself show where to go in the morning to catch the plane to nepal if asked. Finally believe me, you dont need any help if you arrange wheel chair for one of your parents. when my parents were flying to US, i just called both of the airlines and told them that they are going to need wheel chair, they took my parents in wheel chair from the door of the arriving plane in delhi and took them to AA airlines counter, again another wheel chair driver took them from AA counter to the plane seat, and here in chicago, a wheel chair driver took my parents out to the parking lot from the seat of the arriving plane and helped to sit in my car. when i finally sign a paper saying that the wheel chair driver safely and properly served his purpose then only that guy left. now, remember you can request wheel chair in the airport. same day while checking in. it doesnt matter if your parents are physically fit, just ask a wheel chair. more over, the wheel chair driver takes your parents from a seperate security line, so no need for a long wait there. and also parents dont have to walk a single step during the entire travel. My parents had very comfortabel journey both way, My mom didnt even walk a single step,,she had two airhostess to help her even to go to the bathroom everytime in the plane......There is no other better choice than this.

I hope this will help, I also knew this from one of my  friend and did for my parents, surprised by their service. My parents can walk very well though!!