Two polygons are similar if their corresponding angles are congruent and their sides are in proportion.
The sides could be in a ration of 1:1 in which case the two hexagons have corresponding sides that are congruent, but they do not have to be. It could be the case that the sides of one are twice the length of the other so the ratio is 2:1. In this case the hexagons have the same shape but not the same size.
So the answer is this, the corresponding sides of similar hexagons may be congruent but do not have to be.
