How to make the title look like this

Question

I tried something like this. But it is not working. I want to put the author object on the left side, the date object on the right side and below them, the title should come and a line should come below the title

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{geometry}
 \geometry{
 a4paper,
 total={180mm,266mm},
 left=15mm,
 top=14mm,
 }

\setlength{\parindent}{0em}
\setlength{\parskip}{1.4em}  


\newcommand{\HRule}{\rule{\linewidth}{0.5mm}}

\makeatletter% since there's an at-sign (@) in the command name
\renewcommand{\@maketitle}{%
  %\parindent=0pt% don't indent paragraphs in the title block
  {\@author \hfill \@date}
  \par
  \centering
  {\Large \bfseries\textsc{\@title}}
  \HRule\par%
}
\makeatother% resets the meaning of the at-sign (@)

\title{
Motivation Letter
}

\author{
Application for Master of Science\\
Computer Science\\
The University of X\\
}

\date{
Sourav Chakraborty\\
x@gmail.com\\
}

Answer 1

As \@author and \@date may include several lines, I suggest using minipage:

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{geometry}
 \geometry{
 a4paper,
 total={180mm,266mm},
 left=15mm,
 top=14mm,
 }

\setlength{\parindent}{0em}
\setlength{\parskip}{1.4em}  


\newcommand{\HRule}{\rule{\linewidth}{0.5mm}}

\makeatletter% since there's an at-sign (@) in the command name
\renewcommand{\@maketitle}{%
  %\parindent=0pt% don't indent paragraphs in the title block
  {\begin{minipage}[t]{.5\textwidth}\@author\end{minipage}\begin{minipage}[t]{.5\textwidth}\raggedleft\@date\end{minipage}}
  \par
  \centering
  {\Large \bfseries\textsc{\@title}}
  \HRule\par%
}
\makeatother% resets the meaning of the at-sign (@)

\title{Motivation Letter}

\author{%
Application for Master of Science\\
Computer Science\\
The University of X}

\date{%
Sourav Chakraborty\\
x@gmail.com}

\begin{document}
\maketitle

Lorem lipsum...
\end{document}