Q.

Poles have the maximum attraction in a magnet

The magnetic field lines near the center are parallel to the length of the bar. Moreover, the density of the field lines is maximized at the "poles" of the bar magnet and minimized at the center which means that the magnitude of the magnetic field is smallest at the center. That is, in the middle the magnetic lines are far away from one another and at the poles are close to each other which is why at the center the magnetic force is less than the poles.