If the passengers are traveling in Economy (Convenience) they can select your standard seats free of charge any time from the moment you book your flight. While additional charges will apply only on preferred / extra legroom seat selection.
Passengers with special needs requiring specific seating accommodation should contact Qatar Airways so that we can assist with assigning an appropriate seat free of charge with extra legroom seats in the airways. If the passengers are traveling in First Class, Business Class (Elite and Comfort) they can select your seats free of charge any time from the moment you book your flight.