pitṛ-lokaṁ vrajanti te
prajām anu prajāyante
In Bhagavad-gītā, Ninth Chapter, verse 21, it is stated that such persons are elevated to the higher planetary systems. As soon as their lifetimes of fruitive activity are finished, they return to this planet, and thus they go up and come down. Those who are elevated to the higher planets again come back into the same family for which they had too much attachment; they are born, and the fruitive activities continue again until the end of life. There are different prescribed rituals from birth until the end of life, and they are very much attached to such activities.