You may be mistaken. There is no concept of reexamination during the patent examination process. Generally speaking, the applicant will request reexamination only after the patent is rejected.
I guess you are talking about an invention patent, which is about to enter the practical examination stage. You do not need to provide any materials at this time. After the actual examination, the examiner will issue you the first notice of examination action. At this time, you can roughly tell whether your patent application can be authorized. After receiving the first examination action notice from the examiner, you may be required to provide some of your replies or other relevant evidence based on the content therein. However, there is no point in preparing at this time.