What concert is C major on the scale sheet?

A "concert" note refers to the sound that an instrument will make when the note C is fingered. Clarinets and trumpets are concert Bb instruments. A Saxophone is a concert Eb instrument.

This question makes no sense the way it is phrased since concert tuning refers to the relationship between what you will hear when C instruments play a C and what other instruments will sound like.

What do you mean by a scale sheet? Are you trying to ask how the sound of the note C relates to another tone?