You can apply in IOCL on the basis of Gate exam as the application window will be open on 5th-January-2018 as General and OBC (NCL) category candidates must have a secured at least 65% marks in aggregate in the qualifying examination, whereas for SC/ST and PwD candidates the eligibility is minimum 55% aggregate marks.

To know all about IOCL in details, you can go thrrouh the below link -

IOCL 2018

Good Luck!!!