Hello, 

You can choose your own state college in All India Quota but it is usually advised against it. The reason behind this is that in All India Quota counselling students all over India i.e.a very large number of students are competing for a limited number of seats. So the cut off set in the AIQ counselling is usually high. If you choose your own state college then your chances will become slightly less as there is very tough competition for limited seats. It is therefore advisable that you choose the best colleges in the other states as your top priorities and compete for those seats.  Also, apply for state quota counselling separately and choose your preferred college of your state. In state quota only the state candidates will be competing for the seats therefore, a little less number of students will be competing for the seats which might set the cut off to be lesser than the AIQ cut off (estimation).  

Hope this helps.

Good Luck.