they said they have been married for ten years 对吗

不对，结婚是一种动作，不能持续
应该是they said they have married for ten years.

they said they had been married for ten years

对吧

they said there had been married for ten years
be married指结婚了的状态这么用正确
get married 是一时的动作,例如
thay said they got married ten years ago

对

以我之见 应是they said they had married for ten years 不知道是否正确，呵呵····