Watch List notes:

Vaishali District of North Bihar, Vajji Janapada. Anonymous. AR double Karshapna (30.65 mm, 6.59 g). 600-500 B.C. Single Geometrical bold punch in the center / Blank. S. Hirano Type 15. VF, Rare. 

This is also called as Vajji Janapada and is one of the 16 Major Janapadas also called as Maha Janapadas. This is catalogued by Buddhists in Anaguttara Nikaya. Uniface and scyphate with metal added to adjust weight