He suits his customers (6)
I believe the answer is:
tailor
'he' is the definition.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for tailor that I've seen before include "Clothes-maker" , "One makes suits etc. to measure" , "Maker of fitted clothes" , "Maker of clothes for men" , "follower of tinker" .)