Its demonetization, it wasn't well planned, but was necessary at that time. The amount of corruption going around in India goes way beyond than what we speak. The current Prime Minister is trying hard to bring his country to the top, the number of visits he has made to other countries for discussing things and getting things done is astounding. You can poke him how much ever you want, but he's doing something. People were given so many days to convert their money. It wasn't a great move, but it ruined the lives of those who live by corruption, and doing illicit things.
I don't really think it has anything to do with corruption. They tried to go cashless and it backfired. They're walking these steps back now.
Their general anti-crypto sentiment may even be over-correction from this failed attempt. This is nothing but conjecture on my part though.