Sunil Pawar alias Guruji, 41, Mohd. Zuber, 25, Parveen Kumar, 33, and Ranchit Khurana alias Bunty, 30, were arrested earlier this week from different places in the city.
"Sunil Pawar and Zuber used to procure the candidates and then get in touch with Ranchit, who in turn used to obtain the forged documents from Parveen Jha, who used to prepare them," Joint Commissioner of Police (crime branch), Ravindra Yadav said.
So far 22 fake admissions have been detected in Hindu, Kirori Mal, Aurobindo (evening), Kamala Nehru, Shaheed Bhagat Singh, Dyal Singh (evening and morning), PGDAV and Ram Lal Anand colleges.
The modus operandi included preparation of forged documents like mark sheets, migration certificates, degrees, character certificates and caste certificates.
"They even prepared fake degrees of various universities for candidates who were trying for jobs in private sector," Yadav said, adding that stamps, certificates, printers and computers were recovered from their possession.
A case has been registered under various sections of the Indian Penal Code including forgery.
Delhi Police, in June, successfully investigated an admission scam in city schools under the EWS (Economically Weaker Sections) category.