how many many marks is sufficient to get admission in IITs for OBC category according to 2017 cut off?

According, to 2017 cut off you need to get more than 125 marks in JEE Advanced to get IITs in OBC category.

You can also check the cut off rank from the given below link

JEE Advanced Cut off

Good Luck!!

In order to be included in JEE Advanced Rank List for OBC-NCL, you need at least 9.0 per cent marks in each subject, while the minimum aggregate percentage should be 31.5. As per 2016 cutoff, you need at least 8000 rank for admission to IITs. However, with 8000 rank and around it, you may get a new IIT and may not get a branch as per your desire. Thus, you must strive hard to get as higher rank as possible to get better branch and better IIT.

Also, JEE Advanced score/marks are not revealed publicly, so how much score you need for IIT admission is something corresponding to the rank of the candidates, which only they can know.