I guess your country is Bangladesh or India. In these circumstances the crypto exchange markets will go away into the dark internet. You can to use VPN, TOR or other anonymizers to make a transactions. To be honest, it is difficult to ban the crypto currencies from the technical side. The government of your country don't know how to control this market, and they did a mistake, I think.
How can vpn help you? Perhaps you don't understand the problem? You can make transactions in cryptocurrency but what next? In order to sell cryptocurrency for Fiat you need to be able to receive payments to a Bank account or card. In countries where cryptocurrencies are prohibited, this is impossible. How can vpn help you with this?