68 years old male urinates at pathology lab after trying for 3 hrs (urine test) why he has taken so much time? is it prostate or kidney problem?

Urination delay: My first guess to answer your question is that i suspect it is his enlarged prostate gland that may be causing a delay in his urination. Three hours is quite a delay, however. He needs to be examined by a urologist to rule out an obstructing prostate and needs some blood work as well to how well his kidneys are working. I would do so as soon as possible.

either: Either he has poor urine production from kidney disease or urinary obstruction which could be due to enlarged prostate. He needs to see a urologist.