The script of Indus Valley Civilization is still undeciphered
There are too many uncertainties in the Indus script.
Many people said that it is pictorial in nature, alphabetic in nature, and phonetic as well.
The writing style visible to be from the right to the left in many places.
Hence, there is no concrete evidence to suggest that any of the scripts that are currently used in the Indian subcontinent have developed from the Indus script.