Yeah... this is a huge country with lots of potential in this sport - it wouldn´t be hard to get huge crowds of fans if advertised properly... but there´s a lot of strange things in our sposts media & culture here. People normally see sports more like hobbies or simple pastimes than professional entertainment.
Another sport that is huge in NZ and could be big here is netball. Argentina also already have a national netball team but there´s no one to compete with them in this subcontinent.
So do you live in Brazil or Argentina? Because I know in some parts of Argentina there are a decent amount of Rugby followers.