\documentclass{book}
\usepackage{xepersian}
\defpersianfont\nastaliq[Scale=1.1]{XB Zar}

\makeatletter
\newcommand\mycustomraggedright{%
 \if@RTL\raggedleft%
 \else\raggedright%
 \fi}
\def\@part[#1]#2{%
\ifnum \c@secnumdepth >-2\relax
\refstepcounter{part}%
\addcontentsline{toc}{part}{\thepart\hspace{1em}#1}%
\else
\addcontentsline{toc}{part}{#1}%
\fi
\markboth{}{}%
{\centering
\interlinepenalty \@M
\ifnum \c@secnumdepth >-2\relax
 \huge\bfseries \partname\nobreakspace\thepart
\par
%\vskip 20\p@
\vskip -237\p@

\fi
\Huge\bfseries #2\par}%
\@endpart}
\def\@makechapterhead#1{%
\vspace*{28\p@}%
{\parindent \z@ \mycustomraggedright %\@mycustomfont
\ifnum \c@secnumdepth >\m@ne
\if@mainmatter

\huge\bfseries \@chapapp\space {\chapternumber\thechapter}
\par\nobreak
\vskip 20\p@
%\vskip 80\p@
\fi
\fi
\interlinepenalty\@M 
\Huge \bfseries #1\par\nobreak
\vskip 100\p@
}}
\makeatother

\begin{document}
\baselineskip=0.7cm
\tableofcontents 
\newpage\clearpage
\chapter{
مفاهیم اساسی در مورد ابرگروه‌ها
}
\section{اول}
\begin{thebibliography}{99}
\bibitem{a1} 
Atiyah, 
\end{thebibliography}
\end{document}