Betfair may be a desirable gambling platform to play on for you but if your region is restricted then you should forget about it and move on to reputable gambling sites without restriction, if you use a VPN you will still run into trouble in the long run. It's better to stay away than risking your account and funds by bypassing restrictions with the help of a VPN.
Yes if gambling is banned then it is possible to play with VPN but it will not always be effective. The risk will be higher if there is a problem playing according to the government's ban legal action will be taken here therefore it is better to stop getting into trouble.