Kindly let me know whether salah behind a person who makes wudhu by doing masah on normal socks will be valid or not?
If by normal socks you mean the prevalent cotton or nylon socks on which the conditions of masah are not found then masah is not lawful over them. And when wudhu is not valid then salah shall not be valid behind such imam.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband