Ma'Nene' Ceremony is ritual ceremony for contacting the ancestors. In relation to the graves, a ceremony called Ma’nene’ (contacting the ancestor) is performed. This ceremony intended to change the warps of the dead and the clothes of tau-tau. Beyond this, relatives request the well being of their buffaloes, the fertility of their rice and the well being of their children.
This ritual is held by sacrificing buffaloes and pigs. How the ceremony is performed varies from one area to another. It is done after the rice harvest.

Source: LIFE AND DEATH IN toraja by STANISLAUS SANDARUPA