Besides 22.5 per cent such seats already reserved for Scheduled Castes and Scheduled Tribes, the Central Educational Institutions (Reservation in Admission) Bill 2006 introduced in Parliament reserves for Other Backward Classes 27 per cent such seats.

But the Bill says that for reasons of ''financial, physical or academic limitation or... standards of education" the government may permit an institution to increase the intake ''over a maximum period of three years.'' The bill requires such permission by the government to be ''by notification in the Official Gazette.'' The reservation in such cases ''shall be limited'' so that seats available to the OBCs ''for each academic session are commensurate with the increase in the permitted strength for each year,'' it says.

The bill introduced by Human Resource Development Minister Arjun Singh [Images] articulates a move that has triggered students' agitation in the Capital and elsewhere -- but little political opposition.

The agitation has been most pronounced among medicine students, a discipline in which seats are far fewer than, say, in engineering.

As many as 15 per cent seats in each branch of study or faculty are already reserved for Scheduled Castes and 7.5 per cent for Scheduled Tribes.

The Bill defines the OBCs it seeks to benefit as ''the class or classes of citizens who are socially and educationally backward, and are so determined by the Central government.'' India has close to more than 9.95 million students attending 16,885 colleges, but there is no specific estimate of how many of them represent the OBC.

According to the Bill, a central educational institution means: -- A university established or incorporated by or under a Central Act; -- An Institution of national importance set up by an Act of Parliament; -- An institution declared as a deemed university and maintained by or receiving aid from the Central government; -- An institution maintained by or receiving aid from the Central government-- directly or indirectly-- and affiliated to an institution covered under aforementioned categories; -- An education institution set up by the Central government under the Societies Registration Act 1860.

But the reservation will not apply to institutions set up in tribal areas cited in the 6th schedule to the Constitution, 17 specified institutions of excellence, national and strategic importance and a minority educational institution.

Nor will it apply to a course or programme at high levels of specialization -- any postdoctoral studies, which the central government may specify.

The Bill requires ''every central educational institution'' with appropriate approval to raise the number of academic seats so that ''it is not less than'' the number available immediately before Act comes into force.

The Bill has been referred to a Parliamentary panel on HRD ministry for examination, an official said.