6-3

6-3 can refer to the following:
 * World 6-3 from various games
 * Level 6-3 from various games
 * Stage 6-3 from Donkey Kong for the Game Boy
 * Chapter 6-3 from Super Paper Mario
 * Area 6-3 from Mario vs. Donkey Kong: Mini-Land Mayhem!
 * 6-3 Remix (Ice), a sample course in Super Mario Maker