Can i know whether tourists at Hyderabad International Airport can sleep at the airport halls for 5 hours without checking-into a hotel if their departure time is the next day at 1.40 am?
Not a problem. The old standby Sleeping in Airports is on the job. Here is their Hyderabad page. Good luck and safe travels.........d:o)
You can crash at any airport in the world if you have a late flight out, most of the facilities don't close until whatever time after that last flight - you just have to decide how you want to do it. You can sit in a café/bar and gently snooze or just find a quiet corner and doss on your luggage with your jacket over yourself.
Obviously if you are still airside then you need to take a bit of care but once past security then feel comfortable - you can't be there without a ticket and neither can anyone else.