Hi, 

Well for the AIQ there isn't any limit as to how many choices you fill.Moreover in the first round counselling usually it is advised to fill maximum choices in the colleges where you have a chance of getting a seat based on the cutoff of last year.

Try to fill the choices in such a way that the college in which you have maximum chance of getting a seat is filled prior to those in which u have less chance. 

However u need to be more careful during the second round as once a seat has been alloted under the 15% quota seats, you need join and cant resign from it. If u back down from that seat you wont be eligible for further counselling procedure.

As oer state quota the limitation depends on the number of colleges in the state. Mostly theres option which enable u to fill all the colleges as choices. 

Do wise counselling because even that plays an important role in getting you a seat. 

All the best.