\documentclass[oneside]{book}
\usepackage{titlesec}
\usepackage{graphicx}
\usepackage[margin=1.0in]{geometry}
\usepackage{ulem}
\usepackage[hyperindex=true, pagebackref=false,citecolor=orange,plainpages=false, pdfpagelabels]{hyperref}
\hypersetup{colorlinks, linkcolor=blue}
\usepackage{polyglossia}
\usepackage{setspace, bidi}
\setdefaultlanguage[numerals=eastern]{urdu}
\setotherlanguage{english}
\newfontfamily\urdufont[Script=Arabic,Scale=1.5,WordSpace=2]{AlQalam Taj Nastaleeq}
\newfontfamily\nast[Script=Arabic,Scale=1.5,WordSpace=1]{AlQalam Taj Nastaleeq}
\newfontfamily\naskh[Script=Arabic,Scale=1.5,WordSpace=1]{Arabic Typesetting}
\newfontfamily\englishfont[Script=Latin]{Arial}
\renewcommand{\thechapter}{}
\renewcommand{\thesection}{\arabic{section} }
\renewcommand{\labelenumi}{\arabic{enumi}}
\rightfootnoterule
\titleformat{\chapter} {\normalfont\huge\bfseries}{\nast{}\\\ \thechapter}{20pt}{\huge}