Correct Answer - Option 2 : less than 0.8 per cent and more than 6 per cent of the gross sectional area

__Explanation__

__As per IS 456: 2000, clause 26.5.3.1,__

__Longitudinal reinforcement in a column:__

__Percentage of steel:__

The cross-sectional area of longitudinal reinforcement shall be

- not less than 0.8 per cent of the gross cross-sectional area of the column
- nor more than 6 per cent for unlapped bars of the gross cross-sectional area of the column
- nor more than 4 per cent for lapped bars of the gross cross-sectional area of the column

__The minimum diameter of longitudinal reinforcement bars:__

The main longitudinal reinforcement bars used in column shall not be less than 12 mm in diameter.

__The minimum number of longitudinal bar:__

The minimum number of the longitudinal bar provided in column shall be

- four in rectangular columns
- six in circular columns.