Regarding inclusion of "Conclusions"

[kke2]

How can I include the "Conclusions" section after the "Chapters" matter without numbering and reflect this introduced section in "Table of contents" as well?

[GR8DAN]

Your question is ambiguous. To simply stop numbering add the alternative action asterisk. I.e., \chapter*{Conclusions} instead of \chapter{Conclusions}, for a new conclusions chapter, or \section*{Conclusions} instead of \section{Conclusions} for a new conclusion section. The asterisk will prevent the chapter or section from being listed in the TOC.

If you still want it in the TOC see this LaTeX answer:

How to remove chapter numbering without removing it from table of contents

[kke2]

Your question is ambiguous. To simply stop numbering add the alternative action asterisk. I.e., \chapter*{Conclusions} instead of \chapter{Conclusions}, for a new conclusions chapter, or \section*{Conclusions} instead of \section{Conclusions} for a new conclusion section. The asterisk will prevent the chapter or section from being listed in the TOC.

If you still want it in the TOC see this LaTeX answer:

How to remove chapter numbering without removing it from table of contents

Thank you very much for providing a detailed justification in this regard, I have found the solution to my problem through the shared link. Just to indicate, I wanted to add a chapter "Conclusions" without numbering in the main body of the letter and at the same time, it should be imprinted in TOC without numbering. The solution to this problem is (thanks to the reference),

\phantomsection \chapter*{Conclusions} \addcontentsline{toc}{chapter}{Conclusions}