Not very well, seems to be the verdict. Even though 2,357 of them qualified, that number is 210 short of 2,567 seats (27% of 9,509 seats overall) reserved for them. Thus, those extra seats will now go to the general category.
This year marks the third and final stage of OBC reservation -- bringing the total to the full 27%. The quota policy at IITs doesn't work like it does in other institutions: IITs use a cut-off for the reserved categories: for OBC candidates, it's 10% less than the general category cut-off, and for SC and ST, it's 50%.
It turns out that 11.3% (or, 1,489) of the students in the Common Merit List are from OBC -- these are the students who did not need the relaxation in the cut-off. This figure was close to 14 % (~1400) last year.
The share of OBCs among the JEE-qualified candidates (13,104) stands at just under 18%, less than the 2009 figure of 19%.
This is roughly in line with what I said last year:
Out of 1930 students who make it to the OBC list, about 1400 would have made it to the common list without needing a relaxed cut-off. In other words, 14% of the available seats would have gone to the OBC students anyway; this figure was the same last year  too. Thus, a relaxation of 10% in the cut-off marks (both at the subject level and in the aggregate) gets OBCs only an additional 500 seats (or, 5% additional seats).
And here's the thing: the IITs will probably keep this relaxation in cut-off marks at 10%. If the ratio (10% relaxation to 5% additional OBC seats) holds, this would imply that OBCs' share of IIT seats will settle at about 19-20%, and that this share can go up only if the OBCs get into the common pool in greater numbers. [Bold emphasis added].
In the event, OBCs have a smaller share of the common pool this year; as a consequence, they have been unable to fill the seats reserved for them.