The following maps shows four of the sixteen mahajanapadas that existed in ancient India : The places marked A, B, C and D respectively are

The four locations correspond to Matsya (A), Avanti (B), Vatsa (C) and Anga (D). Matsya is shown south of the Haryana region, west of the Yamuna, matching the Matsya mahājanapada on standard maps of the 16 states. Avanti occupied the Malwa/central India region, Vatsa lay in the Ganges–Yamuna doab (with Kausambi as its chief centre), and Anga was the eastern mahājanapada in present‑day Bihar (Champa/Bhagalpur area). These identifications align with standard lists and mapped positions of the mahājanapadas used in textbooks and reference compilations [1].

Sources

1. [1] https://en.wikipedia.org/wiki/Mahajanapadas