Uttara Kriya or After Death Rituals  which is normally performed for a period of 13 days by the deceased son or the Kartha. As per the shastras one should perform Uttara Kriya under the guidance of vedic pandit and should be performed with sincerity, devotion and above all complete faith.

As stated in Garuda Purana, the soul will start the journey after 13th day to Yamapuri (Yakalaoka) and it will take 11 months to reach there, during the journey the soul will not have access to food and water hence it is believed that by performing Uttara kriya and Shraddah and tarpanam by deceased son or the Kartha will satisfy the hunger and the thirst of the soul during its journey