Nice to know, that you would like to help translating Tine 2.0 to Vietnamese.
As I'm not sure if linktech will read the message, I like to point you to https://www.transifex.com/projects/p/tine20/
. There we will coordinate our translation efforts.
Just register with Transifex and create the Vietnamese language team. Then you can start translating Tine 2.0 very quickly.