Question

SODIUM HYDROXIDE is formed near the cathode. why?

Answer 1

During electrolysis of brine(aq. NaCl), NaCl and water are present as electrolyte. 

Na+ (from NaCl) and H+(from water) tends to move to negative terminal (i.e cathode) while Cl- (from NaCl) and OH-(from water) tends to move to positive terminal(i.e anode). 

Now only one from Na+ and H+ at cathode will get reduce which has higher standard reduction potential.

hope it helped