Which of the following statements is incorrect?

a- We get to know about the Harappan civilization from the deciphered scripts.
b- We also get to know from archaeological evidence like pots, ornaments, tools, etc.

Only statement b is correct.

The Harappan seal is possibly the most distinctive artefact of the Harappan or Indus Valley civilization. Made of a stone called steatite, seals like this one often contains animal motifs and signs from a script that remains undeciphered. Yet we know a great deal about the lives of the people who lived in the region from what they left behind – their houses, pots, ornaments, tools, and seals – in other words, from archaeological evidence.