You find a tabanidae that is 6-11 mm long, has long antennae, three ocelli, and distinctly banded wings. this is commonly known as a(n) fly.

Deer   
 The family tabanidae consists of horse flies and other similar flies such as deer flies. So let's look at some distinguishing characteristics of both horse and deer flies.    
 Body Length: Horse flies are 10-30mm, Deer flies are 6-11mm. 
 Antennae: Horse flies have short antennae, Deer flies have long. 
 Ocelli: Horse flies have either vestigial, or entirely lack them. Deer flies have them. 
 Wings: Horse fly wings are clear, uniformly cloudy, or spotted. Deer fly wings are distinctly banded.   

 So on those three characteristics, Deer flies match all of them, while horse flies match none. So the answer is deer fly.