According to open & closing rank of csab special round 1 i should have got cse in iiit manipur (60358-68647 OS obc-ncl rank)
This may be because of the way you would have filled in your choices. If in case you have excluded IIIT manipur from your choice filling list then there is no chance that you could have got it. In case if you have filled it then you might have got some other college which you have filled above it due to which you have not got it. Hope this helps.
It is not only with iiit manipur...
According to OCR i should have got nit agartala,nagaland,and few more