Also 10 per cent seats would be reserved for OBC Category-A and 7 per cent for OBC Category-B.
The total number of seats would be increased so that general category students would not suffer, Panchayat Minister Subrata Mukherjee said after a cabinet meeting.
Higher Education Minister Bratya Basu said that students belonging to the "creamy layer" of the target groups would be excluded from the benefit of reservation.
Early this year, the state Assembly had passed the West Bengal State Higher Educational Institutions (Reservation in Admission) Bill, 2013, paving the way for reservation to SC, ST and OBCs in higher education.
The reservation would be effective in state-funded universities, government and government-aided colleges but not in institutes of excellence, research institutions and institutions of national and strategic importance and educational institutions established and administered by any minority, and specialized courses like super-specialty studies in medicine, engineering and technology, sources said.
It would take about one year to make the ground work before implementation of the new quota system, Mukherjee said.
In respect of institutes which would not be able to complete the capacity expansion for unavoidable reasons, the government would redistribute the reservation quota to other institutes, he explained.