Delatestryl is a test ester. Specifically testosterone ethanate. That has the same actions as testosterone cypionate and the two are considered dose interchangeable.
So that is all rather basic.
You are on the wrong forum for that. This forum is for using large amounts of steroids. You want info about HRT dosing which is covered quite well in the “over 35 lifter” forum.
Post there and have his age, lab numbers, height, weight, fat, fat patterns, dose & frequency and some history. It would be better if he registered, and posted there; and you were not in the middle.
He probably will need an aromatase inhibitor, most do and many consider that an essential component. But most doctors have no idea what they are doing and wonder why one would ever test for E2. That is the problem.