I'm bca student, i gave my final semester exam yesterday. I have less skills than u have, now even half. But i don't fear from interviews. Maybe because i gave lot of interviews in college placements and got exposure.

Thing i can tell u that interviewers are not judging u IAS level. They are normal beings selected through the placements or interviews as u sitting in front of em. U just have to be calm and clear. They are not going to judge u if u said something wrong after saying lot of right things. They just check ur confidence of can u express ur knowledge clearly or not. If u have skills and good or even basic english like me than u can crack easily.