The products of electrolysis of aqueous NaCl solution are

At cathode;Discharge potential of H2O is less than Na+ or SRP of H2O is greater than Na+.H2O is preferentially reduced.At Anode :Discharge potential of H2O is less than Cl- or SOP of H2O is greater than Cl-.Cl-  is preferentially Oxidised.Note: If the electrolyte is very dilute insted of Cl2 at anode O2 is liberated at anode.