Pinky Chaudhary of the Hindu Raksha Dal has taken "full responsibility" of the mob attack that left over 30 injured.
"JNU is a hotbed of anti-national activities. We can't tolerate this. We take full responsibility of the attack in JNU and would like to say that they were our workers," Mr Chaudhary told news agency ANI.
Critics say the fringe group may be working to deflect allegations against the BJP-linked students' group Akhil Bharatiya Vidyarthi Parishad (ABVP).
The Delhi Police are also using face-recognition software to identity the masked people who came armed with sticks and sharp weapons, people with direct knowledge of the matter said. The police are scanning multiple video clips to unmask the attackers, who charged at students and professors after sundown on the campus.