The students, numbering around 200, had gathered in front of the collectorate to submit a memorandum to the District Collector on lack of basic infrastructure and amenities at the college in Kovaipudur, police said.
But police prevented their entry following which a heated argument broke out.
As the students did not heed their advice to disperse, a senior police official ordered their arrest and about 120 students were taken into custody, they said.
Police, quoting some students, said they had come to observe a day long fast to draw the attention of the District Collector to the conditions prevailing in the college.