Hello dear aspirant.
As per current reservation system 50%seats are reserved for OBC sc St ph and other minority sections.
Remaining 50%seats are for the general category candidates but in this category also some of reservation candidates can enter with good marks.
Hope it helps.
50% of the seats in all the IITs, NITs and GFTIs are unreserved and open to general candidates so technically 50% of the available seats in all the cse at different different IITs are filled by general candidates. Moreover, with the introduction of 10% reservation for Economically weaker sections(EWS) of the society. This further increased the number of general candidates.
You could check the detailed list(seat matrix) of IITs here .