Assertion:  Harappan Civilisation is dated between c.1500 and 500 BCE.
Reason: The Harappan civilization is sometimes called the Mature Harappan culture to distinguish it from the earlier and later civilisations in the same area.

The Assertion is incorrect but the Reason is correct.

Named after Harappa, the first site where this unique culture was discovered, the civilisation is dated between c. 2600 and 1900 BCE. There were earlier and later cultures, often called Early Harappan and Late Harappan, in the same area. The Harappan civilisation is sometimes called the Mature Harappan culture to distinguish it from these cultures.