For which ancestors is Tarpan offered in Gaya?

Tarpan is typically offered for three preceding generations (father, grandfather, great-grandfather; mother, paternal grandmother, paternal great-grandmother) and maternal ancestors (maternal grandfather, etc.). Specific Tarpan can also be done for other departed relatives, friends, or even souls one wishes to help. During Pitru Paksha, specific days are associated with particular relations (e.g., Navami for mothers).