Dear student,
its really easy to understand
Every student appearing for AIPMT are eligible under 15% all india quota, if selected under this category a student from Karnataka can even get a college in Bihar, student from gujarat can get a college seat in kerala etc etc. This is a separate category of around 7-8 thousand seats from all the govt. or private institutions over the country. Each and every medical college give their 15% of total seats to this category. rest 75% seats in the colleges are reserved exclusively only for their state children , this is called the state quota seat.
this means that for you, among all the seats available in colleges of delhi, 75% will only be for students who have either studied or born in delhi. And you even have chances to get any college acroiss the country if selected under All India quota.

every aipmt aspirant will be given several rank lists:
1: All India Quota list- shows your rank among all the aspirants countrywide.
2: State ranklist- shows rank only among aspirants of your state.
3:Category ranklist: shows rank only among students of your category(UR,SC,OBC etc)