The quick answer is no, it is not. Roulette isn't rigged online for the same reason that the game isn't rigged in person, the casino doesn't need to rig the game to make their money! Double zero roulette, by far the most common version of the game being played today, has a built-in house advantage of just over 5%.
This means that you cannot predict the exact number where the ball will land. But you only need to know which area of the wheel the ball will land and you can gain a massive advantage over the casino more than 40%.