I just want to ask 2 questions. First, what will be the possible content of a preliminary part of a Math masters thesis? Second, can I use any part of a book in a sense that copy it and then include it on the preliminary part with a proper citation or do I need to restate it on my own words? Thanks a lot in your help.
Your preliminary section should perhaps introduce the problem you tackled and the steps taken to attack it. It should serve as a sort of overview, moreso than an abstract.
I would not copy verbatim anything from a book in bulk unless you have the consent of the author or publisher to do so. At my university, students are required to have these "copyright statements" if they are reusing printed material that they have already published. I would check your university's guidelines on these.