I'd have to find out tommorow. My bus is 65 passenger, but I never bothered to find out the weight. If nobody else gets to it, I'll let you know. But for now, the closest I can get is a 72 passenger bus which weighs 13157 KG(28999 LB).
Are you wondering about the weight of the bus itself, or the maximum gross weight, including occupants and their belongings? Empty weight on a 65 passenger bus is probably about 16000 lbs. give or take. A contractor in this area running 84 passenger TC2000s has the empty weight posted on the side and that is in the 17000 lb neighborhood.