Are there any map sources other than bing in india?
Usefull are the Digitalglobe images. In some areas there are only bing images of low resolution but better images of Digitalglobe.
Using JOSM, you have to activate the Mapbox Satellite entry.
Can it be used on Potlach?
I always use JOSM. As far as I know, these images cann’t be used in Potlach but in ID (a newer online-editor).