Is it permissible to eat chicken provided by SriLankan Airlines based on the flight attendant's assurance that it is halal, knowing that the majority of people in Sri Lanka are Buddhists?

The default ruling for slaughtered animals is prohibition, and it is not permissible to eat unless one knows for certain that it has been slaughtered according to Islamic law. The word of a Buddhist regarding his slaughtered animal being ritually slaughtered is not acceptable, as he is not among those whose slaughter is considered valid. If the prevailing religion in a country is Buddhism, then it is not permissible to eat unless one inquires and confirms its lawfulness. It was obligatory to ask the hostess about the slaughterer, and if her truthfulness was strongly presumed, then it would be permissible to eat.