As far as I have heard is that govt is considering HNI who ever in 2017 have bought btc worth over 1lac till now. So I think majorly they will want the tax to be paid on the profits earned since people who had invested before 3-4 months and by now if they hold would have made good profits. So tax notice would be sent to them.
Investing is not a taxable event. Selling for rupees is a taxable event. What if someone purchased in current tax year (after April 2017) and did not sell? How does he have tax liability and why would he receive notice for tax evasion?
May I ask the source of this information?