Flight Chhatrapati Shivaji International Airport departs from Mumbai Chhatrapati Shivaji International Airport at 23:10 and arrives at Hanoi Noi Bai International Airport at 05:00.
The flighttime is about 4h 20m. The distance travelled ("as the bird flies"): 3662 Km. So the average speed is roughly 845 Km.
There is an 1.5 hour time difference between Mumbai and Hanoi