When did Thailand host the first international 80 kg welterweight rugby tournament ?
The national domestic Thailand Rugby Union ( TRU ) competition includes several universities and services teams such as Chulalongkorn University , Mahasarakham University , Kasetsart University , Prince of Songkla University , Thammasat University , Rangsit University , the Thai Police , the Thai Army , the Thai Navy and the Royal Thai Air Force .