It depends on the exact Ts&Cs of that cover and on what cover you may already have under other policies...
Read the policy details carefully, as there are a lot of these low-cost schemes going around which - when you read the fine print - turn out to cover you only when away from home and/or travelling other than in your own car, i.e. in another person's car or by public transport. In which case you're probably better covered under their insurance, and for nil premium from yourself.
You wouldn't normally expect to get much by way of life/motor/health insurance for 6 euro a month, so I'd expect that whatever you're being offered by way of an (undiscriminating) mailshot probably has some serious restrictions on it. Including a proviso to the effect that any payout will be reduced by any other compensation to which you may be entitled from other sources (including VHI, etc.)