Each of the four Tzitziot of a Talit Katan or Talit Gadol consists of four stringswhich are folded to create eight strings, and a total of six knots are tied at different intervals. Within each interval are differing numbers of coils; according to the Shulhan Aruch (O.H. 11:14), the number of coils per interval, starting from the one closest to the corner of the garment, are seven, nine, eleven and thirteen. According to the Arizal, however, the number of coils are seven, eight, eleven and thirteen, and Rabbi David Ovadia (Nahagu Ha’am, Hilchot Tzitzit) says that a mnemonic to remember this order is Zman Hayenu Ya’arich Yagdil(7, 8, 11, 13). The reason for this order is because if seven and eight are added together, it is equivalent to Yud-Ke, which is one of Hashem’s Names, and if eleven is added to this total it is equivalent to Yud-Ke-Vav-Ke, and thirteen is the same numerical value as the word Ehad (One). The HIDA (Birke Yosef) gives a third opinion and says that number of coils per interval are ten, five, six and five, symbolizing the Name of Hashem Yud-Ke-Vav-Ke.
According to Rabbi Shalom Messas (Shemesh Umagen, vol. III, § 32) and Rabbi Yehoshua Maman, the Moroccan custom is for the Talit Katan to follow the order of ten, five, six and five, and for the Talit Gadol seven, eight, eleven and thirteen, and it is unclear why there is a distinction between the two types of Talit. Nevertheless, these are not Halachically binding and if one were to wear a Talit Katan with the same number of coils as a Talit Gadol, for example, it would not be a problem.
It is important to note that according to the letter of the law, the only knot which is Halachically significant is the first double-knot closest to the garment; the subsequent knots are simply a custom. Although it is important that all the knots be intact, if some or all but the first double-knot are undone, it does not affect the fulfillment of the Mitzvah of Tzitzit.
Summary: The Moroccan custom is that in the Talit Katan the knots are separated by ten, five, six and five coils while the Talit Gadol has an order of seven, eight, eleven and thirteen. One fulfills the Mitzvah regardless of number and order of coils one wears.