GST is non-cumulative. What it essentially means is that you get credit for input GST paid. So a trader who buys and sells bitcoin would only pay GST on the profits that he makes.
Thanks for clarifying this issue!
However, wouldn't the profit being taxed under GST, and the same amount being taxed as Income/ Corporate Tax become double taxation?
That Input GST credit is a complex beast. Even the biggest companies, like Patanjali (per interview with their CEO), are suffering because they are not getting it right.
Also, this GST will dispose of any remaining chances of using Cryptocurrency for day-to-day transactions in India. It's far simpler to use a mobile wallet like PayTM, which doesn't involve any such GST calculations.