(b)any special provision for the advancement of any economically weaker sections of citizens other than the classes mentioned in clauses (4) and (5) in so far as such special provisions relate to their admission to educational institutions including private educational institutions, whether aided or unaided by the State, other than the minority educational institutions referred to in clause (1) of article 30, which in the case of reservation would be in addition to the existing reservations and subject to a maximum of ten per cent. of the total seats in each category.