As per Hindu religion after death a person becomes 'Pitra'. At the same time it is being said that 'Atma' is 'azar and amar' and takes new body/shape after death.
Does it mean that 'Pitra' is without 'Atma'?
What is the difference between 'Pitra' and 'Atma'?
Pitra are those people who died unnatural death and did not get salvation. Due to this, people perform remedies for the pacification of Pitra Dosha.
While Atma is Azar and Amar, Pitra is not. Pitra has atma, but needs purification from pitra dosha. Once it is purified, it can take rebirth as per Hindu religion.
For details, I suggest, you visit some ashram or guruji in your neighbourbood or meet a swamiji in Ramakarishna Mission or Bharat Sevashram Sangha.