First, it's the twelve tribes of Israel. Secondly this is kind of a tricky question.
Israel aka Jacob had 12 sons.
Reuben
Simeon
Levi
Judah
Dan
Gad
Naftali
Issachar
Zebulun
Asher
Joseph
Benjamin
But when counting the tribes, Joseph is not mentioned. Rather we have the names of Joseph's two sons, Ephraim and Manasseh, who are each counted as half tribes.
So there are 13 names but 12 tribes
Reuben
Simeon
Levi
Judah
Dan
Gad
Naftali
Issachar
Zebulun
Asher
Ephraim/Manasseh (Joseph)
Benjamin