Income Tax authorities of India, is now providing online PAN search for individuals. Link is https://incometaxindiaefiling.gov.in/knowpan/knowpan.do
Considering the population of 1+ billion population, even if we assume 40% working population, we are targeting 40-50 million working population. On further hypothesis of 30-40% having PAN number, roughly 15-20 million PAN numbers are available for search.
This is definitely not small number by any feat. More-over response time is quite fast. BTW, now with e-filling of income taxes, IT department is now going to the the global standards. Kudos to IT department of India, way to go.