How many choices of postdoc jobs a PhD student normally get? At the end of the PhD experience, how many choices of postdoc jobs a student can normally get?

It depends totally from the PhD supervisors or there can be other factors influencing the matter, such as e.g. the student desire to join a particular university/research group, the PhD research topic, number and quality of papers?

Thanks
There are really no answers to your question. It depends on so many factors:
* If you're from Harvard or Berkeley, your adviser is well known, and you've been doing excellent work, then you might get offers from essentially all places you choose to apply.
* If you're from Middle-of-Nowhere City College, worked on some obscure research topic that was started by your adviser 40 years ago and that nobody cared about at the time (and cares even less about today), and did not publish, then you may get no offers from any of the places you apply to.

In addition, it of course depends on where you apply, how many applications you send, whether you carefully choose your letter writers, if you have many/few publications, if you're willing to look overseas, etc. There is no generic answer to your question.