For which ancestors is Tarpan specifically offered in Varanasi?

Tarpan is generally offered to the immediate three preceding generations (father/mother line), maternal ancestors, and other departed relatives (siblings, uncles, aunts), Gurus, friends, and even unknown souls (through ‘Sarva Pitru Tarpan’). Performing these rites in Varanasi is believed to benefit all departed souls connected to the performer