The reaction of glycolysis is follows:
C6H12O6 + 2 NAD+ + 2 ADP + 2 P -----> 2 pyruvic acid + 2 ATP + 2 NADH + 2 H+
A glucose molecule produces 2 mole of pyruvic acid. For glycolysis, 2 molecule of NAD+ reduce to NADH by oxidising the glucose molecule to produce acid along with the production of 2 protons. This complete reaction, generates 2 mole of ATP.