The prime accused has been identified as Alok Kumar, a B Tech graduate who cleared the NMIMS entrance test several times by impersonating real applicants.
About 87 students cleared NMIMS Management Aptitude Test (NMAT) for the MBA batch of 2013, police said, adding that about 22 students cleared the test and got admissions in 2011.
Five other accused, who acted as mediators, have been identified as Hanumant Singh Gujar, Sugriv Gujar who are both BTech graduates and brothers, besides Brajendra Pratap Singh, MBA graduate Pavan Kumar and Himanshu Shekhar, the police said.
The gang charged Rs 15 lakh per student, they said.
The first five accused were held from Delhi, while Himanshu was nabbed from Pune in the last seven days.
On behalf of the NMIMS, the NMAT test is conducted by Pearson VUE, the world's largest education company that develops and delivers over 10 million computer-based tests across 175 countries, police said.
"A month ago, the NMIMS complained to us about possible fraudulent practices being carried during online tests for NMAT 2013. During the course of the investigation, we caught all the six accused who used to charge Rs 15 lakh per student to ensure that they clear the NMAT test," Joint Police Commissioner (Crime) Himanshu Roy said.
Explaining the modus operandi, Roy said the Gujar brothers, Singh and Pavan Kumar looked for prospective candidates who desired NMIMS admissions but had no capability to clear the online NMAT aptitude test on their own.
"The gang promised students passing marks in the NMAT exam through the management quota. For online exam, a student could approach any of the centres spread all over India. The accused filled up the admission form of students online, where photographs of applicants were not required," Roy said.
"The gang then prepared a driving license, Aadhar card or PAN card with the original details of students, but attached a photograph of Alok Kumar, who visited different examination centres and appeared for the aptitude test," he said.
Over 20 people, including seven who took NMAT on behalf of applicants, are wanted in the case, police said.
The gang is suspected to have been involved in the admission racket for at least three years, while educational consultancy firms like Career Guardian in Uttar Pradesh and Meta Consultancy in Delhi have been found to be involved in such malpractices, they said.
"It was NMIMS which first noticed these possible fraudulent practices in the online NMAT test and took the matter to the Mumbai police. The Crime branch has done a commendable job by exposing those involved in such practices and we will extend full help in their investigation," NMIMS University Vice-Chancellor Rajan Saxena said.