Some of my favourite writers live in South East Asia. Most of them aren’t as well-known as they should be. I asked Joyce Chng, a Singaporean writer and a friend, if she could help. This gives you somewhere to start. Then you can move on to Victor Ocampo’s lists (to which Joyce gives a link), and keep reading. She says:
Southeast Asia is also home to a small group of established and up-and-coming science fiction and fantasy writers. Believe it or not, we are also writing science fiction for a while now. This is a short list of writers who are either currently residents of the said countries or living in the West.
Joyce Chng/J. Damask
S. P. Somtow
Aliette de Bodard
Victor Ocampo has a more detailed list on his website.