Indian/South Asian, British Indian, Indo-Caribbean reggae artists...

Indian:

Delhi Sultanate (Taru Dalmia) - Delhi-based reggae/hip-hop artist I recently came across.

Reggae India - new Delhi reggae collective: Abood, Priyanka Singh, Raghav Dang, and Zorawar Shukla

Nepali:

Samba - Nepali singer. Seems to do covers of English songs (sometimes with Nepali mixed in). But apparently only one professionally recorded song, "Get Up, Stand Up", with video.

Sri Lankan:

Jayashri - I don't know very much about them, but they seem to be popular in Sri Lanka. Do they sing in Sinhala or Tamil (or both)? Austrian-based, I believe.

British Indian:

Apache Indian (Steven Kapur) - Well-known British-born Indian (Panjabi) reggae/ragga/bhangramuffin/bhangragga artist.

Asian Dub Foundation - Rap, dub, dancehall, electronica.

The Dub Factory (Parvez) - Roots reggae meets qawwali ! Brilliant stuff, on which more later.

Indo-Jamaican:

Super Cat (William Maragh)