Why is Neo the sixth One and not the seventh? In numerology seven is the number that represents the end of a cycle, such as the 7 days of Genesis or the 7 days of the week. Also in numerology, the letters of "Neo" mean 5-5-6 which when all added come to 16 or 7 (1+6).

But on the seventh day God rested as he saw that his work was completed, which also points to the fact that the seventh Matrix might be the final product, ready to be shipped out for sale. And it was on the sixth day that man was created. Either way, the possibility of Merovingian being a former One would tie neatly into the seven Ones theory, but there are other possibilities. There was a mention of him on the comments as being Hades, the Greek god of the underworld who was Persephone's husband. However, another more likely choice would be associating him with Lucifer, the leader of the fallen angels who were cast away from heaven by God because of their actions. This would tie together the fact that the Merovingian keeps werewolves and vampires around him and they are described as "older programs."

The scene of the cake also points to that aspect since his action is worthy of a demon, and the descendents of the Merovingians, the sect of the Cathars, were considered as heretics by the Catholic Church in the Middle Ages and accused of witchcraft. The Agent on the highway calls the Keymaker an "exile." Another indication that points towards the angelic nature is the Oracle's bodyguard, Seraph, whose name is that of a class of angels.

In that case the Merovingian could be either be a One that never completed its mission or a fallen angel, a program designed to look over the Matrix that rebelled against the keepers of the Matrix. But if he is a former One, which one then? I suspect that the Architect has left out something very important in his conversation with Neo about the past of the Matrix.

For example, he says that the first Matrix (the one where humans lived in pleasure) was a monumental failure, but how did it end? Would it make any sense to send a One to bring it down? The Architect mentions that this is the sixth Matrix but that the concept of Zion was only created after the failure of the first so it would make sense if Neo is the fifth One, and in biblical symbology 5 is the number of man (5 senses, 5 fingers, 5 members including the head). The restaurant is at floor 101, or 5 in binary. The first Matrix also has some interesting points in common with the Bible. It was a Paradise for humans but they ended being cast away from it, like Adam and Eve who were also expelled from Eden for disobeying God's command.

p.s. Remember the 314 seconds mentioned by the Keymaker as the time they have for entering the building? Also, do you remember what the Architect says right afterwards? Now, how is this for a coincidence? “Turn, O backsliding children, saith the LORD; for I am married unto you: and I will take you one of a city, and two of a family, and I will bring you to Zion” – Jeremiah 3:14.

Source: matrixessays.blogspot.com