how to say they play rugby in french

The natural way to say it is « Ils jouent au rugby. » if “they” is a mixed group or all male, and « Elles jouent au rugby. » if the group is all female. French uses jouer au for rugby, and “rugby” stays rugby in French.

Quick breakdown

• Ils = they (mixed group or all male).
• Elles = they (all female).
• jouent = play.
• au rugby = rugby.

Example

• Ils jouent au rugby tous les samedis.
  They play rugby every Saturday.

If you want, I can also give you the pronunciation in French.