The Kotoritana Republic is not mentioned in either anime adaptation, being manga-only.
For reference it is noted in the manga that the Kotoritana Republic (and by analogy Greed Island) is about the size of real-life Hokkaido island of Japan (approximately 83,450 km²/32,220 sq. mi.).[note 1]
↑The Viz translation erroneously presents the size of Hokkaido as being "~83,000 sq. mi. -ed", quantifying the size of the island in miles (which would result in a different value) rather than kilometers.