Although chlorine is an electron withdrawing group, yet it is ortho-para directing in nature in electrophilic aromatic substitution because when chlorine is present in benzene ring, it releases electron by resonance whereas it acts as withdrawing group only through inductive effect. By inductive effect, chlorine atom destabilizes the intermediate carbocation formation but by resonance, chlorine atom stabilises the intermediate carbocation and effect is more at o and p-positions. Resonance effect opposes inductive effect. Inductive is stronger than resonance effect due to which reactivity is controlled by inductive effect and orientation by resonance.
