Provided that there shall not be more than four such visiting Professors in a University at any given time.

Appointment in accordance with promotion schemes .- Notwithstanding anything contained in section 48 but subject to the rules and orders issued by the Government from time to time for reservation of appointments and posts for Scheduled Castes, Scheduled Tribes and other Backward Classes, appointments to the posts of Readers and Professors in University Institutions and Departments may be made by the Syndicate with a promotion scheme, if any, prescribed by Statutes in this behalf, if the