Timor Leste beat Brunei 3-2 on aggregate despite losing the second leg 1-0 in Bandar Seri Begawan last weekend.
The 2018 AFF Cup is the 12th edition of the AFF Championship and the 6th since being rebranded as the AFF Suzuki Cup.
In the 2018 season, the ASEAN Football Federation (AFF) adopted a new format for the 10 finalists.
According to the results of the last two seasons in 2014 and 2016, nine teams have qualified for the final round, including Thailand, Vietnam, Indonesia, Malaysia, Singapore, Philippines, Myanmar, Laos and Cambodia. Timor Leste and Brunei had to play a two-leg playoff match for a place in the finals.
This is only the second time Timor Leste has made it through to the finals of the AFF cup since 2004. Timor now join Thailand, Indonesia, Philippines and Singapore in Group B, while Group A features Vietnam, Malaysia, Myanmar, Cambodia and Laos.
The final tournament will run from November 8 to December 15.
In the group stage, there is no host country. Instead, each team will play four matches, including two home games and two away matches. The top two teams of each group will enter the semi-finals.
The semi-finals and final match are played in a home and away format to determine the winning team based on the final result. The two finalists will have to play a total of eight matches.
According to the AFF draw, Vietnam will play two away games against Laos on November 8 and Myanmar on November 20, along with two matches at home at Hanoi’s My Dinh Stadium with Malaysia on November 16 and Cambodia on November 24.
Coach Park Hang-seo’s side will gather from October 11 with a squad of 28 players.