Impermissibility of Tazia during Muharram

This is an invalid practice which was not practised in the time of Nabi (sallallahu alaihi wa sallam), the sahaabah (radhiyallahu anhum) and the taabi`een. It was initiated by the shiahs who are a deviant group whom many ulama don't even consider as Muslims. Further, many of these practices commenced from fire worshippers and hindus.

And Allah Ta'ala (الله تعالى) knows best.