I was under the impression that Azam Ali identifies herself as an Iranian who grew up in India. Though either way, there are extensive ties to both cultures - and her music (with Vas and solo) incorporates many other influences as well. Anyway, her music is fairly distinctive, and I don't know if there's anyone
really like her - but you might check out Lisa Gerrard, either solo or as half of Dead Can Dance.
Aion may be a good match for Ali's
Portals of Grace. The soundtracks may not be as representative of the sort of music you're after.) You can find many excerpts of the music at Amazon, iTunes, etc.