Here is the summary. And I am quoting actual numbers from News Paper Reports.
News Report; 5% Odisha Resident students. [Including perhaps those also who would be Odia by their citizenship, irrespective of where they stay]
My estimate; a typical 10% general category students, going by how large the quota regime entails in terms of percentage toward quota qualifiers.
News Paper Report; Lying vacant per anum, 10%.
My reasoning; if there would be no quota based qualification system perhaps these seats would never lay vacant, plus we would have far superior engineers produced in the country. Because the 3-levels of quota scrutiny sees the merit off to such a level even 10% seats lay vacant, at the same level that gets admitted after fierce scrutiny.