6B

6B or VI-B may refer to :
* Keratin 6B, a type II cytokeratin
* Oflag VI-B, a World War II German POW camp for officers located 5 km (3 miles) SW of the small town Dössel
* REL-6B Radar, a ground air surveillance and guidance radar
* Rumpler 6B, a 1916 German single-engine floatplane fighter
* Season 6B, a popular fan theory related to the long-running British science fiction television series Doctor Who
* Stalag VI-B, a Nazi World War II camp for prisoners of war
* TUIfly Nordic IATA airline designator

6b may refer to :
* 6 bits, like in 6b/8b encoding