How many prakritis of Mandal Theory of State are enumerated by Kautilya?

In Book VI of Kautilya’s Arthashastra, the Rajamandala (circle of states) comprises twelve categories of kings/states (headed by the Vijigishu). Each of the twelve states possesses six material constituent prakritis (Amatya, Janapada, Durga, Kosha, Danda, and Mitra, alongside the 12 sovereigns, or 12 × 6 = 72), yielding 72 prakritis in the expanded Mandala theory.