The Harappan civilization existed in the Indus Valley from 2600 BCE to 1900 BCE. The Harappan script, which was used by the inhabitants of the Indus Valley, is considered to be one of the oldest scripts in the world. However, the script has not been deciphered completely, and its relation to the modern Indian scripts is still a subject of debate.

Explanation:

The closest Indian script to the Harappan script is the Dravidian script. The reasons for this are:

1. Geographical proximity: The Harappan civilization was located in the northwestern part of the Indian subcontinent, while the Dravidian-speaking regions were located in the southern part of the subcontinent. The fact that the Harappan script has more similarities with the Dravidian script than with any other Indian script suggests that the Dravidian-speaking regions were in close contact with the Harappan civilization.

2. Linguistic similarities: The Dravidian languages, which include Tamil, Telugu, Kannada, and Malayalam, are distinct from the Indo-Aryan languages, which include Hindi, Bengali, and Punjabi. The Harappan script has more similarities with the Dravidian script than with the Indo-Aryan scripts. This suggests that the Harappan language may have been related to the Dravidian languages.

3. Phonetics: The Harappan script is a pictographic script, which means that it uses pictures to represent words and ideas. The Dravidian script also uses pictographic elements to represent sounds and words. This suggests that the Harappan script may have been phonetic, like the Dravidian script.

In conclusion, while the Harappan script has not been deciphered completely, the evidence suggests that it was closer to the Dravidian script than to any other Indian script.