To characterise diameter of capillaries in organs
This question is dependent on the specific patient at hand.
I think in the normal situation the diameter of the capillaries is about the same in each organ.
Better question would be: how does the diameter changes in relation to the venous and arterial ends of the capillaries?
Then, think about how big portion of the capillaries are in the venous end in the organ.

I cannot say that 50% of capillaries are on the venous end of the organ and 50% on the arterial side.
This is again an open research question.