As I have appeared in both of the exams through which we can get these two jobs. Staff Selection Commission conduct CGL exam through which we can be appointed as sub inspector in CBI and SSC also conduct SSC CPO exam through which we can be appointed as sub inspector in delhi police.
Both post are the most powerful and reputed but here it is depend upon your field of interest like if you want to get a civil uniform with stars on shoulders then you can go with this job.
CBI sub inspector job is more reputed than SI in delhi police but it has its cons that it is very hectic job. In this job you can be called for work anytime.
So we can choose with our own interest.
