India was the birthplace of plumbing, though the Romans perfected it.
Standardized earthen plumbing pipes with broad flanges making use of asphalt for preventing leakages appeared in the urban settlements of the Indus Valley Civilization by 2700 B.C.[5]
I am not in the position to judge the situation in India but invention does not necessarily imply widespread adoption. Or adoption may change over time, for example by not keep up with population growth.