As far as I know, Tran is the Viet Namese transliteration of 陳 Ch’en/Chen, a very common Chinese surname. It’s properly written Trần.
When I see someone named Trần, I figure they’re ethnic Chinese from Viet Nam. However, I just checked and 11% of the population of VN is named Trần, so it seems they’re not all ethnic Chinese.
Be that as it may, the name originates in China. It’s one of the five most common surnames in China. From seventy to eighty million people have this name. Some countries don’t have that many people! Pretty impressive.