According to the most recent World Rugby Rankings as of September 19, 2023, Tonga is ranked 16th in the world. However, it is important to note that these rankings are constantly changing based on the results of international matches, and the rankings are calculated using a points exchange system that takes into account factors such as the relative strength of each team, the margin of victory, and home advantage. It is also worth noting that there are separate rankings for rugby union and rugby league, and the rankings mentioned in the search results are for rugby union.