Well it seems u r expressing your fury over non-reply of Forum fellows regarding interview matter. Buddy, there is no pet pattern of interview n u can,t confine yourself to any specific field while preparing for interview. Interview panel mostly pertains to 4-5 members. Some time very irrelevant questions r asked n sometime very basic. It absolutely depends on the discretion of committee members. U need not to become very conscious about interview preparation. U have already fallen in top 100 out of 8500 candidates which is certainly honor for u. Rest role, ur destiny will play. Least bother yourself for interview preparation and just make rehearsal in privacy for expected questions. The most repeated introductory questions are:

Describe yourself
Why u should be selected for the post
Why you want to join this department
Why u want to leave ur current employer (if already employee)
Why you should be preferred for this post over other candidates
Explain your five negative as well as plus points

Prepare best answers of above questions in privacy. Try to be fluent in your reply. Don’t give pause to your fluency. Wherever, u feel that u can’t reply, simply say sorry, instead u fall in deep thinking. Have a slight look on basic Islamic study, Pak study, Ur basic law terminologies (applicable to IB/agencies), acquaint yourself with great confidence, self belief, coolness n faith in Allah. Gud Luck