The best way to submit a book written in Indian Language is to convert it to PDF and embed all the fonts in the PDF. If you have Adobe Distiller, you can use that to convert your MS word or other files into PDF. Otherwise, there are pretty good free PDF converters like cutepdf, which you can use for the same. In some converters you may need to change settings to ensure that all the fonts are embedded.

Of course, you should conform to the other generic specifications for creating interior and cover files as well.