The incident comes in the wake of Chief Minister Siddaramaiah's warning against moral policing in the state.
The victim has been identified as Vinay Kumar.
He is studying at Paramedical College in Bhadravati.
He was beaten up by a team of Muslim men after a Muslim girl student took a drop from him as her sister met with an accident on Saturday, the police said.
While the victims were returning, the group waylaid them and sought their identities and all of a sudden, they attacked Kumar, police said.
The group also attacked Kumar's two friends, Abhi and Yeshwanth, when they rushed to the spot and tried to rescue him.
The police have arrested four accused, and are in the hunt for the fifth, Shivamogga SP Mithun Kumar said.
The Old Town Police has registered a case in this regard under IPC 506 (threatening with life), 504 (intentional insult), 143 (unlawful assembly), 147 (guilty of rioting), 149 (offence committed by unlawful assembly) and 323 (assault).
Stringent action against those who take law into their hands, SP said.
(With UNI inputs)