Question about centring text and adding borders to table of contents

Question

I want to do two things in my document

1. Add borders to my table of contents
2. Centre/align the title of table to title of the page

In the following image, I am only showing the contents (not the whole page, the rest of it is blank). This is how I want my page to look:

My code is as follows, firstly I have a class file called Vakalatnama.cls which contains the majority of code:

\ProvidesClass{vakalatnama}[2020/09/15 Vakalatnama template for Indian courts]

\LoadClass{article}

\RequirePackage{xparse}
\RequirePackage[driver=xetex,a4paper,noheadfoot,includeheadfoot,nomarginpar,top=1.5in,bottom=1.5in,left=1.75in,right=1.0in]{geometry}
\RequirePackage{xunicode}
% \RequirePackage{xltxtra}

% Make entries in the index table as links
\RequirePackage[linktocpage=true]{hyperref}

% Set font to Times New Roman
\RequirePackage{fontspec}
\setmainfont{Times New Roman}

% line spacing = 1.5
\RequirePackage[onehalfspacing]{setspace}

\RequirePackage[parfill]{parskip}

% Format section title to have numbers in Table of Contents, but not in document
\newcommand\secpagebreak{}
\RequirePackage{titlesec}
\titleformat{\section}{\center \normalfont \bfseries}{}{0pt}{\secpagebreak}
\setcounter{section}{1}

\RequirePackage{fontenc}
\hyphenation{con-sti-tu-tion-al}

% Set title of Table of Contents from Contents -> Particulars. '*' implies that
% the argument must not be in multiple paragraphs i.e. /long
\renewcommand*{\contentsname}{
    \par\noindent\hspace*{\fill} \textbf{\underline{Index}} \hspace*{\fill} \\*
    \hspace*{-10pt}\underline{{\textbf{Si. No.}}} \hfill \underline{\textbf{Particulars}} \hfill \underline{\textbf{Page}}
}

\newcommand{\pnp}{Test Solicitor}
\newcommand{\dhc}{Delhi High Court}
\newcommand{\sci}{Supreme Court of India}
\newcommand{\petitioner}[1]{\newcommand{\@petitioner}{#1}}
\newcommand{\respondent}[1]{\newcommand{\respndt}{#1}}
\newcommand{\court}[1]{\newcommand{\crt}{#1}}
\newcommand{\jurisdiction}[1]{\newcommand{\jurisdctn}{#1}}
\newcommand{\petitiontype}[1]{\newcommand{\ptntype}{#1}}

\NewDocumentCommand {\setname} {O{Shri} m m} { % Title (default=Shri), first, last
    \newcommand {\tfname} {#1 #2 #3} % Full name with title
    \newcommand {\fname} {#2 #3} % first + last name
    \newcommand {\tlname} {#1 #3} % title + last name
}

\newcommand{\advocate}[2][Shri]{
    \newcommand{\adv}{#2}
    \newcommand{\fulladv}{#1 #2}
}


\newcommand{\clientdetails}[1]{\newcommand{\clntdtls}{#1}}

\newcommand{\caseNumbers}[2]{
    \newcommand{\fullcasenumber}{#1 of #2}
    \newcommand{\shortcasenumber}{#1/#2}
}


\newcommand{\casetitle}{
    \begin{center}
        \textsc{In the \crt{}} \newline
        \textsc{\jurisdctn{}} \newline
        \textsc{\ptntype{} \fullcasenumber{}} \newline
    \end{center}
}

\newcommand{\inmatterof}{%
        \begin{tabular}{l c r}
             \multicolumn{3}{l}{\underline{\textsc{In the matter of:}}}  \tabularnewline
             \tabularnewline
             \@petitioner & \ldots & Petitioner \\* %\tabularnewline
             \multicolumn{3}{c}{-- \textsc{versus} --} \tabularnewline
             \respndt & \ldots & Respondent \tabularnewline
        \end{tabular}
}

\newcommand{\parties}{%
    \begin {center}
        \begin{tabular}{l c r}
             \@petitioner & \ldots & Appellant/Petitioner \tabularnewline
             \multicolumn{3}{c}{-- \textsc{Between/And} --} \tabularnewline
             \respndt & \ldots & Defendant/Respondent/Opposite Party \tabularnewline
        \end{tabular}
    \end{center}
}

\newcommand{\tophead}{%Roll the Court Name, petition etc into a single command
    \casetitle{}
    \inmatterof{}
}

\renewcommand \maketitle {
    % Cover page
    \thispagestyle{empty}
    \pagenumbering{gobble}

    \casetitle{}

    \inmatterof{}

    \vspace*{5em}
    \tableofcontents
    \vspace*{5em}

    \textbf{Advocate for the Respondent: \respndt{}}

    \renewcommand\secpagebreak{\clearpage}
}

\ProcessOptions\relax
\endinput

And then main.tex

\begin{document}

\petitioner{Test Petitioner}
\court{Supreme Court Of India}
\respondent{State of Uttar Pradesh and Others}
\jurisdiction{Criminal Appellate Jurisdiction}
\petitiontype{SLP (Civil)}
\caseNumbers{1152}{2000}
\advocate{\pnp}
\clientdetails{Test Petitioner}

\maketitle
\setcounter{page}{1}
\pagenumbering{arabic}

\section{Vakalatnama}
\section{Memo of Appearance}

\end{document}

Thank you in advance for your help :-)

Answer 1

I used etoc package as follows in my class file:

% Format Table of Contents
\RequirePackage{etoc}
\newcommand{\titleoftoc}{\textsc{Index}}
\newcommand{\mktoc}{% Cover page
\begin{center}
    \etocsetstyle{section}
    {}
    {\etociffirst{ \\ \hline}{\\\hline}}
    {\etocnumber & \etocname & \etocnumber }
    {}
    \etocsettocstyle{\hypersetup{hidelinks}
    \begin{tabular}{|c|l|c|}
        \multicolumn{3}{c}{\titleoftoc} \\
        \hline
        \multicolumn{1}{|c|}{\bfseries Si No} &
        {\bfseries Particulars} &
        {\bfseries Page}
    }
    {\\ \hline\end{tabular}}
\etocglobaldefs
\etocsetnexttocdepth{1}
\tableofcontents
\end{center}
}

Afterwards, in main.tex

\begin{document}

    % Set other paramaters

    \mktitle
    \section{AAA}
    \section{BBB}
\end{document}