Zechariah 12-14 has broad repetition of the deliverance of Jerusalem from the latter day invaders and of the coming of Messiah. Based on The Oxford Encyclopaedia of Books of the Bible (2011) we have
A. 12:1-9 Deliverance of Jerusalem
B. 12:10-13:1 Sacrifice of Messiah
C. 13:2-6(5) Cleansing of the land from false teaching
B’. 13: (6)7-9 Suffering of Messiah
A’. 14:1-21 Deliverance and elevation of Jerusalem
I would like to make one departure from the Oxford Encycl. 13:6 is clearly Messianic and it would be a mistake to read it as attached to the false prophet of verse 5. If the chiasm boundary is slightly amended then it fits well with the Messianic parallel of the crucifixion in chapter 12. The centre of the chiasm emphasises the important theme of the whole prophecy – that Jerusalem once more will be a City of Truth.