If it has to be six letters, you could spell "atwain" which means, archaic. : in twain : in two parts : asunder.
If you can do it in five letters, you could use "await", "twain", and "witan" which is another term for an Anglo-Saxon national council or parliament.
I have to say, four letters would be easier, because you could use "twin", "want", "anti", wain", and "wait".
