Dont get confused with the Different denominations of Categories. Everyone is alloted an AIR on the basis of his/her marks..without any special specification of OBC, SC, ST or PD. Its all under genereal category that means no specification.
After that according to the reservation quota new ranking list of respective category is generated for seats which are reserved in different branches in different colleges. SO that those seats can only be occupied by OBC ST SC & PD candidates. But to judge their presence they are alloted different rankings.
For your rank all above your AIR are in general Category but they are specified with special Category ranks, so in case a OBC candidate with his GEN or AIR rank 7000 will be preferred for some seat if OBC reservations are available cz he'll have less OBC rank then you
All the best!!!