If the benficiary of the will dies before the testator, then the legacy would lapse and it will form a part of the testator's property. However, if the testator had expressed in his will that on the death of beneficary, the property shall devolve on some other person then it will not lapse but devolve on the other person so specified.
For the Legal representative of the beneficary to inherit the propery, it must be proved that the testator died before the death of the beneficary. If it cannot be proved who died first then also the lagacy would lapse.
If the lagacy is in favour of two persons and one of them dies, the legacy would not lapse and devolve on the surviving beneficary.
The Legal representatives of the beneficiary (donee), who didnot survive the testator(donor) cannot claim any right in the property.