It wouldn't go down to zero but will definitely reduce. The startups created around crypto ecosystem will also reduce. It will also accelerate the great India brain drain regime that we are currently experiencing. Also it will encourage people to take illegal routes to cash out their cryptos.
I believe that's what the government wants especcially when RBI governor is very much pushing towards a blanket ban.
But who cares when incompetent people chairing the highest positions within finance ministry.
Won't be a big loss to the government, innovative and talented people aren't useful to the ruling party, unemployed idiots who are willing to engage in riots are their true assets.