Hi Likhita,
Hope you are doing well. There is no restriction for number of colleges in option entry. You can enter any number of colleges and any number of branches of your choice. And it is not only applicable for the first time. Every time when you enter the options, there is no restrictions for number of options. But the thing to be kept in mind while entering options is that you should put options based on your preferences. The first preferred college should be kept in first position and continued further. I hope this answer helps you.

Best of luck.