Tetum is a member of the Malayo-Polynesian branch of the Austronesian language family. Tetum is spoken by about 800,000 people mainly in East Timor (Timór Lorosa'e / Timor-Leste), where is has been an official language, along with Portuguese, since 2002 when East Timor became independant. It is also spoken in West Timor, which is part of Indonesia.
source
wikipedia.org,
omniglot.com &
ethnologue.com