I know most local lottery have almost the same rules, winners are urge to claim their winning, some are months abut some at least within a year after the draw, that's the rule related to claiming here in my area for national lottery, but it is recommended to claim it asap. So that 6 months is still good if you win here, in US the national Powerball lottery only have 6 months expiry after the draw.
So if you are buying lottery tickets make sure you read and follow its rules first to understand what will you do if you win.
When we talk about local lotteries or lotteries that we are participating in real life, it's definitely our responsibility to go and find out the winner after the draw and if we are the winner, we should claim the prize because we are not asked for your personal address or mailing address or anything when buying tickets so that the money can be sent to you, and it's not their responsibility either, they wouldn't take the risk of delivery the money on your doorsteps and would want you to come and claim it with the ticket in your possession.
However, when it's to online lotteries, the scenario would be different since the platform where you participate in a lottery must ask you to create an account first, and in case you win the lottery, the amount should be added to your account, and then they should give you a specific deadline for you to withdraw the funds before they confiscate them.