You can use any of these marker sets to delimit the indian language text. The marker names indian/marathi/hindi/tamil do not actually do anything by themselves, but make use of the corresponding command names to load in the IFM file or output the font changing command string. So, use any one of the sets you feel suits your needs best.
To set the IFM file name: \indianifm=XXX.ifm
To set the font command name: \indianfont=YYY
Start Marker: \indian
End Marker: \endindian
To set the IFM file name: \hindiifm=XXX.ifm
To set the font command name: \hindifont=YYY
Start Marker: \hindi
End Marker: \endhindi
(follow above examples, replace indian with marathi.)
(follow above examples, replace indian with sanskrit.)
(follow above examples, replace indian with tamil.)