Teams from how many countries have competed teams in the Olympic Rugby Union competitions until 2016?

Answer 1

6
In 1900, there were teams from France, Great Britain and Germany. In 1908, there were teams from Australasia and Great Britain. In 1920, there were teams from France and the USA. In 1924, there were teams from the USA, France and Romania. After 1924 Rugby Union was not included in the Olympics again until 2016 when the Sevens version was introduced.