Can I substiute Indian Chillies instead of Mexican chilli peppers for a mole sauce?

The country of origin isn't important. Some chili peppers are hotter than others. The round ones that look a bit like shrivelled tomatoes are quite fiery.

The link below grades chili peppers by heat.

All chilies (red peppers) originate from the North & South America, and likewise .. even though black pepper (white pepper) are grown in S.America it originally comes from India/Asia.

There are many varieties of chilies grown around the world now, so you will want to find a similar variety , if you want the same taste.

You can use habanero, jalapeño, Thai chilies etc the difference is the mole sauce will taste spicer than those dried pastilles chilies '

Yes it tasty with either