You can read the book online via Bookmate , which lists the Gujarati edition published by Eka.
: Upon arriving in Meluha, Shiva's throat turns blue after consuming the medicinal Somras, leading the people to hail him as their savior. The Gujarati Translation
Amazon India has the Gujarati edition available for Kindle. While it’s typically in KFX/AZW3 format (not standard PDF), you can read it on any Kindle app. Search for "The Immortals of Meluha (Gujarati)".