Seeing dead parents, relatives, husband, wife, grand parents, brother or sisters in dreams is considered bad as per those who believe in dream interpretation. In Hindu religion there is an ancient scripture known as Swapna Shastra which gives interpretation and meaning of various dreams.
The main belief is that the soul of the dead person seen in the dream is not at peace and is still wandering on earth.
Those people who see such dreams are advised to read Bhagavad Gita.
Another option is to do food donation – feed poor children and elderly.
It is also advised to perform Shradh rituals to the dead during Mahalaya period especially at