Moodle has language packs for at least 75 languages, I'm quite sure Hindi is one of them.
They change the Moodle User interface when chosen.
The quiz itself you can write directly in Hindi. (Since Moodle supports UTF-8 unicode it supports most languages (including maths!))
There are various alternatives for adding mathematical symbols in Moodle. There are a built-in "algebra" and "TeX" filters (that the site administrator can enable.) One can also use pictures and there are a number of plug-ins that I haven't had time to try.
Visit
http://docs.moodle.org/en/Mathematics