Ariya Desha (अर्य) in Jain cosmology refers to the northern half of the world. The two main divisions are:

• Uttara Ariya Desha (northern Ariya Desha)
• Dakshina Ariya Desha (southern Ariya Desha)

There isn’t a standard, canonical list of Ariya Desha names arranged alphabetically. So there isn’t a universally accepted “first” Ariya Desha name starting with a specific letter like K. The Deshas are described more in terms of north vs south and their cosmological features, rather than a fixed alphabetical sequence. If you want, I can share more about how Uttara Ariya Desha is described in Jain texts and its sub-regions.

You can read more here