𝗧𝗵𝗲 𝗿𝗼𝗮𝗱𝗺𝗮𝗽 𝗳𝗼𝗿 𝘄𝗼𝗿𝘀𝗵𝗶𝗽 𝗼𝗳 𝗼𝘂𝗿 𝗣𝗶𝘁𝗵𝗿𝘂𝘀

𝗧𝗵𝗲 𝗿𝗼𝗮𝗱𝗺𝗮𝗽 𝗳𝗼𝗿 𝘄𝗼𝗿𝘀𝗵𝗶𝗽 𝗼𝗳 𝗼𝘂𝗿 𝗣𝗶𝘁𝗵𝗿𝘂𝘀

We have to understand (I mean in our HIndu traditions) that when a person dies and his Sapindeekaranam is effected he attains a slot in the pitruloka as Vasu..

Immediately his father gets promoted to Rudra staus and his father in turn gets Aditya staus.

And the Vriddha Prapitamaha is released from the Pinda staus and he and his earlier two generations are now in the Lepa status.

The womanfolk join their mother in laws in the same pattern, according to our beliefs and traditions

In Pinda status the pitrus get the balls of rice or grain whichare offered as pindam and the Lepa pitrus are getting only the remnants of pindam which stick to the hand of the one who does the pitrukaryam.

Again the Vasu Rudra and Aditya positions are just slots assigned to the pitrus and not the spirits themselves.

The pitrus may assume other lives but the offerings sent to the slots or posts through Swadhaa Swaahaa and Mahavishnu reach these slots get recycled into materials suitable for the Pitrus in their present lives and status and get safely delivered to them.

Such offerings from various lives all get delivered in the present address as if redirected.

The three generations rule is just a convention. There are some Pitrupoojas where even ten or twentyone generations are invoked

And Shraddham is a vedic ritual and that can offer temporary relief to the pitrus.

You can call such relief as moksham if you want.

But real moksham can be gained only by the individual himself that too through jnana, karma or bhakti yoga.

That suject is too wide