Although chlorine is an electron withdrawing group, yet it is ortho - , paradirecting in electrophilic aromatic substitution reactions. Why ?

Explanation

Chlorine withdraws electrons through inductive effect and releases electrons through resonance. Through inductive effect, chlorine destabilies the intermediate carbocation formed during the electrophilic substitution reaction.
Through reasonance, halogen tends to stabilise the carbocation and the effect is more pronounced at ortho - and para - positions. The inductive effect is stronger than resonance and causes net electron withdrawal and thus cause net deactivation. The resonance effect tends to oppose the inductive effect for the attack at ortho - and para - positions and hence makes the deactivation less for ortho - and para - attack. Reactivity is thus controlled by the stronger inductive effect and orientation is controlled by resonance effect.