I am quite new to LaTeX and I am trying to make a document with both Tibetan and Devanagari script. I know one can use XeLaTeX to use different Unicode scripts directly in your code, but for whatever reason, all I get when I compile is question marks where the script should be. What do I need to change to get this to work properly? I have looked in many manuals and searched this site but I haven't seen an explanation of this. I am using a Mac. Thank you.
\documentclass{article}
\usepackage{fontspec}
\setmainfont{Arial Unicode MS}
\begin{document}
བོད་ཡིག་ཡང་ཡོང་གི་ཡོད་མ་རེད།
शारदा शारदाम्भोजवदना वदनाम्बुजे।
सर्वदा सर्वदास्माकं संनिधिं संनिधिं क्रियात्।।
\end{document}
