بسم الله الرحمن الرحيم
(Fatwa: 676/598/M=06/1440)
If you want to keep the word Hadi in the name of your son then you should prefix it with Abd and keep the name Abdul Hadi or Muhammad al-Hadi. You can call your son by the name Muhammad as well.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband
