Dear aspirant,

It's not necessary to apply for more than  one universities, if you are confident enough to grab a seat in your first prefered college it's good for you. But, if there is even a slight chance that you can loose your seat in your preferred college, than it's better to have some backups with you for your own safety. By applying in more than one universities you can expect a seat in any of them and than later choose the best one for you.

Hope this helped, good luck with your future!