Which is the best site for the online mock test series for the JEE Main (earlier AIEEE)?

There are many online and offline test series available. But it’s best to not go for local test series. Try to join a test series of a national-level coaching institute. Reputed national coachings usually have a vast number of candidates all across the nation. The difficulty level of the test series will also be similar to that of JEE Main. By taking these test series, you will also get to know your approximate position nationally.