In European Roulette, the RTP is 97.3% no matter what you bet. This means that for every 100 you stake, you can expect to get 97.3. Of course, in the short term, you can win anything from roulette because luck plays its part.
While it is theoretically possible to make a living off of playing roulette, it is extremely difficult and highly unlikely. Roulette is a game of chance, and the house always has an edge, which means that over time, the odds are in favor of the casino.