\documentclass{article}
 \usepackage[no-config,no-math]{fontspec}  % font selection for xelatex
 \usepackage{xunicode}                % unicode character support

%\trimFrame  
%\settrimmedsize {15cm}{25cm}{*} 
%\settrims{20mm}{34mm}

%\usepackage{polyglossia}
%\setdefaultlanguage{marathi}
%\setotherlanguage{English}

%\setmainfont[Script=Devanagari,Mapping=devanagarinumerals,Path={/xfonts/devanagari/jaini}]{Jaini}
%----------------------------------------------------------
% Jaini
% https://ektype.in/jaini-1106.html
%----------------------------------------------------------
\setmainfont[
  ExternalLocation,
  Script         = {Devanagari},
  Path           = {/xfonts/devanagari/jaini/},
  Extension      = {.ttf},
  UprightFont    = {*-Regular},
  BoldFont       = {*-Regular},
  ItalicFont     = {*Purva-Regular},
  BoldItalicFont = {*-Regular},
  Ligatures      = {NoCommon},% e.g. "fi" be represented as a single character?
  Mapping        = {devanagarinumerals},
  ]{Jaini}

\newfontfamily{\Jn}[
  ExternalLocation,
  Script         = {Devanagari},
  Path           = {/xfonts/devanagari/jaini/},
  Extension      = {.ttf},
  UprightFont    = {*-Regular},
  BoldFont       = {*-Regular},
  ItalicFont     = {*Purva-Regular},
  BoldItalicFont = {*-Regular},
  Ligatures      = {NoCommon},% e.g. "fi" be represented as a single character?
  %Mapping        = {devanagarinumerals},
  ]{Jaini}

%----------------------------------------------------------
% Heuristica
% "Heuristica is extended version of Adobe Utopia font"
% http://code.google.com/p/evristika/
% SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
%----------------------------------------------------------
 \newfontfamily{\Sb}[
   ExternalLocation,
   Path           = {/xfonts/heuristica/},
   Extension      = {.otf},
   UprightFont    = {*-Regular},
   BoldFont       = {*-Bold},
   ItalicFont     = {*-Italic},
   BoldItalicFont = {*-BoldItalic},
   Ligatures      = {NoCommon},% e.g. "fi" be represented as a single character?
   ]{Heuristica}

\begin {document}

{\Sb As main font- }\\{\Huge ज्ञानेश्वरी , वल्लभ}

{\Sb As a specified font (this is how
  it shold look like)-}\\{ \Jn\Huge ज्ञानेश्वरी, वल्लभ} 
\end{document}

