There are two possibilities here:-
a. On the menu in an Indian restaurant, 'rogan' means red...eg rogan josh = red meat.
b. In the Algonquin - ie Canadian Indian - language, a 'rogan' is a watertight container made from birch-bark.
Yes, it means meat fat
the Josh part of the indian dish literally means heat.
Traditionally the fatty meat on the bone was used for making Rogan Josh and it was slow cooked in its own fat with extra added for an intense flavour.