According to Garuda Purana the souls that don't get Pind Daan, Tarpan and so forth meander erratically on the Earth. Pitru paksha or Shradh is a 16-lunar day period, where Hindus remember their ancestors during that period. This usually falls in the fortnight immediately after the Ganesha festival, which is in the second fortnight of the Hindu calendar month of Bhadrapada. This puja is specifically suitable for Success in Business or Career , Protection from Evils and Enemies. Shradh custom is done to satisfy the dissatisfied wishes of the predecessor's souls which are caught in our reality because of powerful urges that stay in soul even after death.
Book Pandit for Shradh puja in Pune.