The source of copper for the Harappans was Rajasthan.

Harappan Civilization:
The Harappan civilization, also known as the Indus Valley civilization, flourished around 2600 to 1900 BCE in the western part of South Asia, primarily in present-day Pakistan and northwest India. This ancient civilization was known for its well-planned cities, advanced infrastructure, and sophisticated trade networks.

Copper in Harappan Civilization:
Copper was an essential metal in the Harappan civilization and was used for various purposes, including tools, weapons, ornaments, and vessels. The Harappans were skilled in metallurgy and had the technology to extract and manipulate copper.

Sources of Copper:
The Harappans obtained copper from various sources, including:

1. Karnataka:
Karnataka is a state in southern India that has rich copper deposits. However, there is limited evidence to suggest that the Harappans sourced copper from Karnataka. The main copper mining activity in Karnataka started much later, during the medieval period.

2. Andhra Pradesh:
Andhra Pradesh, another state in southern India, has also been a significant copper-producing region. However, there is no strong evidence to suggest that the Harappans sourced copper from Andhra Pradesh.

3. Gujarat:
Gujarat, a state in western India, is known for its copper deposits. The Harappans had established trade connections with Gujarat, and archaeological excavations at Harappan sites have revealed copper artifacts that are believed to have originated from Gujarat. Therefore, Gujarat is a possible source of copper for the Harappans.

4. Rajasthan:
Rajasthan, a state in northwestern India, is considered the primary source of copper for the Harappans. The Khetri copper mines in Rajasthan were one of the largest copper-producing regions during the Harappan period. Numerous copper artifacts found at Harappan sites have been traced back to Rajasthan, further supporting the theory that it was the main source of copper for the Harappans.

In conclusion, while Gujarat also played a role in the copper supply for the Harappans, the primary source of copper for the Harappans was Rajasthan. The Khetri copper mines in Rajasthan provided the necessary raw material for the production of copper artifacts in the Harappan civilization.