The A6M6 mod. 53, designated as the Type 0 Carrier-based Fighter Model 53 (零式艦上戦闘機五三型), was a prototype on the A6M5 mod. 52C (Hei) developed to carry the Sakae 31a engine, featuring a water-methanol engine boost which slightly improves engine power but during testing proved unsatisfactory due to the unreliability of the prototype engine. It also includes fuel tanks that were made self-sealing.

It was introduced during Update "Red Skies" as a reward for Battle Pass: Season IV, "Fearless Voltigeur". Essentially the "black sheep" of the Zero family together with the A6M5 mod.52 Hei, the A6M6 sacrifices manoeuvrability for more armament, ordnance, and survivability, though at a much larger degree. While it is noticeably less capable in dogfighting compared to its peers, the A6M6's improved protection means that it can afford to take punishment, making it very forgiving to fly. The plane's reinforced airframe also makes the A6M6 highly capable at boom-and-zoom tactics and high speed dogfights, especially when using snap turns to catch the enemy off-guard. It is also capable of ground attacking due to the generous amount of machine gun rounds and payload.