What you *can* do is:
* Apply to multiple universities: Apply to several universities and accept an offer from one. Then, if you later change your mind or get a better offer, you can withdraw your acceptance from the first university.
* Defer at one university, then apply elsewhere: If you defer your acceptance at one university, you are free to apply to other universities during your deferral period. You would then need to decide which offer you want to accept.
* Receive multiple deferral offers (unlikely, but possible): It's *possible* to receive deferral offers from multiple universities, but you'd still only defer at one. The other offers would simply be kept on hold until the following year (when you'd decide whether to accept one).
In short, the concept of "deferring to multiple universities simultaneously" is not standard practice. You manage your applications and admissions separately for each institution.