what is the average tax rate on income in India? - that would help in evaluating if 30% on crypto currency is much or not.
The top most bracket is 43% on regular income. However gains from capital assets are being taxed at a concessional rate. For example stocks, if held for more than 12 months are taxed at a rate of 10% (and 15% in case they are being held for less than that duration).