We can answer it with "YES" & "NO" both.

Country can ban Cryptocurrency and their exchanges with legal rules as they like. Like recently in India when RBI said that they will ban it - banks connected with exchange stopped taking Deposit and Withdrawals and all the money freeze in exchange as no one able to withdraw it through banks. But later exchanges come up with solution like Peer to Peer, Coupons any many more so it started as usual. Even government ban it people will find a way to ignore it and do it anyway. As they may ban things under their border but not beyond that.

There is many possibilities for this. So as said we can answer with "Yes" as well as "No"