You have to face two examinations on the same day.. You cab give the MAINS exam only if you clear PRELIMS and then the physical and medical tests. Prelim exam has 4 sections - Quantitative Aptitude, Logical Reasoning, English and General Studies of 50 marks each. Then the MAINS exam only has English subject. After marking you a final cut off list of candidates comes out and if you are amongst top 5-7% people to get through you will be recruited as police INSPECTOR in Delhi Police.