Dear Monica,

You can choose as many colleges as you want. It may be 50,100 or so. But remember to fill in your choices from best to a bit good. You will be alloted a college according to the order you have submitted.Counselling will be done till all the seats are filled. According to your state rank and neet marks you will be allotted a seat in subsequent counselling phase. 

So basically you can fill as many colleges you want but be aware about the order or preference. Good luck!

Monica,

            There is no limitation for this. You can apply for as much college as you want. To get a complete list of colleges, you may eligible for, you can always use https://medicine.careers360.com/neet-college-predictor tool.

Regards