Thanks all for replying and looking for the deals. I forgot to mention some of the *KEY* points.

He can't take any flight which is coming to USA as he doesn't have US visa(right this time).

He had NWA tickets bought yesterday online for ~2300 which had the same routing but they didn't allow to board him as the flight wasn't coming as INTL flight to Minneapolis and Immigration didn't (obviously) cleared him at the gate. Luckily he bought the ticket less than 24 hrs so was able to got the full refund.

He is going thru counter to counter at airport and looking for the options. I think he will take one way option either thru Frankfurt as Lufthansa has direct flight to Hyderabad.