Youngsters, mostly students from different city colleges, assembled on the pavement across Hotel Taj near the Gateway of India to condemn the violence.
It was an "impromptu assembly at a short notice, a student said.
Violence broke out at Jawaharlal Nehru University on Sunday night as masked men armed with sticks and rods attacked students and teachers and damaged property on the campus, prompting the administration to call in police which conducted a flag march.
At least 28 people, including JNU Students' Union president Aishe Ghosh, were injured as chaos reigned on the campus for nearly two hours.
Eyewitnesses alleged the attackers entered the premises when a meeting was being held by JNU Teachers' Association on the issue of violence on campus and assaulted students and professors. They also barged into three hostels. Video footage aired by some TV channels showed a group of men, who were brandishing hockey sticks and rods, moving around a building.
The Left-controlled JNUSU and the RSS-backed ABVP blamed each other for the incident.