Is there anyone that knows about Australian immigration?

[Needsomebloodyperspective]

My sons father moved to Australia 11 years ago and is now a citizen. My son who is now an adult has moved over there for a year and would like to stay, can he get citizenship based on his fathers status?

His father doesn’t seem to think so, but I don’t think that is true. There is a whole horrible backstory to this, that o won’t go into. I feel like his dad doesn’t want him there and is making this up. Thank you.

DS would only be eligible for citizenship by descent if his dad was an Australian citizen at the time of his birth, which it doesn’t sound as though he was. DS therefore needs to apply via other routes if he wants to stay.

There is an Australia and New Zealand-board.
Lots of good advice there.

https://www.mumsnet.com/talk/aussie-nz-mumsnetters

I don't know the ins and outs, but I think he could apply for a visa if his father sponsors his application?

I thought there was a remaining relative visa? I’ve been looking into it.

If he has only be there for a year he can work at least another 2 on a working visa. He could also find an employer who is willing to sponsor him for a visa.

Australia are notoriously strict. The remaining relative visa won’t apply as he is not DS last remaining relative, as you live outside Aus.
As a PP said, your son would be better off trying to get sponsorship via work.