Before the cremation is about to start, the eldest son of deceased person or another male mourner (often referred to as the lead cremator or lead mourner) bathes himself in the river to get ready for the rituals. Then the lead mourner who has shaved his head (except for a little tail, called sikha) gets ready to perform the ritual with the help of a priest, who conducts rituals while preparing some food offerings.
The concept behind shaving the head is that it is an offer to the gods which represents a real sacrifice of beauty, hence shaving your head shows your grief for the departed soul.

Before the cremation is about to start, the eldest son of deceased person or another male mourner (often referred to as the lead cremator or lead mourner) bathes himself in the river to get ready for the rituals. Then the lead mourner who has shaved his head (except for a little tail, called sikha) gets ready to perform the ritual with the help of a priest, who conducts rituals while preparing some food offerings.
The concept behind shaving the head is that it is an offer to the gods which represents a real sacrifice of beauty, hence shaving your head shows your grief for the departed soul.