Odd Man Out

All except Mob represent well- organised group.

All other taxes are levied and collected by the centre.

Each of the numbers except 399, is one more than the square of a certain number.

In all other groups, the first and second as well as the third and fourth letters are consecutive and the third letter is nine steps ahead of the second.

In all other groups, the first and second as well as the third and fourth letters are alternate, and the third letter is three steps ahead of the second letter.

All except Rice are rabi crops, while rice is a kharif crop.

All others are preliminary stages of an experiment.

All except Sailor need raw materials to work on..

In all other pairs, second is the antonym of first.

In all other groups, the fourth, first and third letters are alternate letters in order.