No team of the Top 14 (1st league championship) in Nice. But the stade Niçois plays in the 2nd amateur league, a good amateur level. The club exists since 1912.
Matches in the Allianz Riviera stadium. If yo like rugby, why not go and see them play?
The best team in the area, no need to say if you're a rugby lover, is Toulon RC. They won the french championship several times and even the European H cup. Wilkinson used to play there.
The Toulon RC sometimes plays its matches in Nice, in the A. Riviera stadium.