At the Indian University of Hyderabad they found iron artefacts that can be dated as early as 2145 BC. Is also possible, as often happen that the date can be older. This mean that old stone carving was made by Indians who then expanded this art to the others Classic Cultures associated.
As a matter of fact, the Tutankhamun’s Dagger like the Iron Column in New Delhi doesn’t rust even after centuries.
See the paper of the findings here: https://www.academia.edu/37685699/Iron_Age_in_South_India_Telangana_and_Andhra_Pradesh
Note that in the paper above you’ll see Indian Sarcophagi made of stone like the ones used in Egypt.
Also Megalithic Monuments: “It is well known that the megalithic monuments from Europe are well related to the celestial bodies (Heggie 1981; Tom 1954:396-404). But, as far as the Indian megaliths are concerned, except passing references to such relationship, especially with the Sun, no systematic study has been carried out so far”.