بسم الله الرحمن الرحيم
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 Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.