If a person has been missing for a long period, then cremation of the person can be performed as per Hinduism. In cases where there is sufficient evidence to believe that an individual may have died, and neither the body nor its parts are available for cremation, Hindu dharmashastras recommend the ritual of akritidahana, which involves religiously burning an effigy of the person.
The effigy is meticulously crafted from 360 palasha (Butea
frondosa) stalks and leaves. These stalks are allocated according to prescribed
proportions, such as 40 pieces for the head, 20 for the chest, 30 for the
abdomen, and so forth. If the person had maintained the Vedic fires,
sacrificial vessels are also consigned to the fire, mirroring the customary
cremation process when the physical body is present.
In the event that the person is still alive and returns, all
the samskaras or sacraments must be performed anew, including the act of
remarrying his own wife.