The panel also found that students Umar Khalid and Anirban Bhattacharya facilitated the unauthorised entry of some people to the campus.
The panel said it "unfortunate" that the students allowed that to happen.
The panel has also pointed out lapses on part of the university's security unit, saying it did not make any efforts to stop outsiders from shouting provocative slogans and stop them from leaving the campus.
"The organisers disobeyed the instructions from the administration about not holding the event. This amounts to willful defiance. It is most unfortunate that the organisers allowed the event to be taken over by a group of outsiders who created a charged atmosphere by raising provocative slogans.
"This act by outsiders has brought disrepute to the entire JNU community," the report of the five-member panel said.
"The committee also notes that none of the JNUSU office-bearers acted with due responsibility. The office-bearers had to behave with even more restraint and caution befitting the position they hold.
"They need to rise above the politics and other differences as they represent the student community. It is unbecoming of student representatives that they should be found engaging in disorderly conduct or condoning it," it added.
The report has two sections -- findings and recommendations. The section of findings has been shared by the university with 21 students who have been issued a show-cause notice in this connection, the recommendations have been kept out of public domain.
Highly-placed sources in the university had said that the panel, which submitted its report on March 11, has recommended rustication of five students including JNU Students' Union president Kanhaiya Kumar, Umar Khalid and Anirban Bhattacharya who are facing sedition charge.
While the panel has identified a few students guilty of procuring permission from the university on false pretext, it has also noted that the Dean of Students (DoS) should have withdrawn the permission in writing and not by sending text message to the Chief Security Officer.
"It has to be noted that since the event had taken place in 2015 as well, the Dean's office was not vigilant enough to anticipate and prevent this event. Security did not make any efforts to stop outsiders from shouting provocative slogans and prevent them from leaving the campus," the report said.
OneIndia News (With agency inputs)