NewsMeter performed a reverse image search and found several news reports from September 2021 indicating that the idol was found at Sellandiamman temple in Namakkal district of Tamil Nadu.
According to a report by Puthiyathalaimurai, a Tamil Nadu-based media organisation, the idol was discovered at the Sellandiamman temple when authorities dug a trench in front of the temple to build a perimeter wall.
The same was reported by other news outlets such as Dinamalar and Vikatan. "Work is currently underway to renovate the Sellandiamman Temple…workers dug the soil in front of the Pondicherry temple to build a perimeter wall. At that time, they saw an old Nandi idol buried in the soil and informed the temple authorities about it," reported Vikatan.