https://www.makersmakings.org/what-is-transmigration/

Transmigration of soul will not be a rebirth or a reincarnation.

The words rebirth and reincarnation are denoting a start from the womb of a physically current mother. On the contrary, transmigration of soul will not be so.

Transmigration of soul is denoting the method of taking over the bodily vehicle of one other one who is already current upon the bodily world. Transmigration is undergone after an

entity crosses previous the stage from where beginning from the womb of a bodily mother can take place.

But as a result of the macrocosmic laws are equally relevant to each microcosm, so this process of taking on the physical vehicle of one other person can solely start after an

agreement is made with that particular person and that too within the delicate or astral worlds.