Okay, so Ronaldo wants to play in CL. These are the clubs which participate this year:
ENG: Chelsea, Liverpool, Manchester City, Tottenham
ESP: Atlético, Barcelona, Real Madrid, Sevilla
GER: Bayern, Dortmund, Frankfurt, Leipzig, Leverkusen
ITA: Inter, Juventus, Milan, Napoli
POR: Benfica, Porto, Sporting CP
FRA: Marseille, Paris
AUT: Salzburg
BEL: Club Brugge
CZE: Viktoria Plzeň
ISR: Maccabi Haifa
NED: Ajax
SCO: Celtic
UKR: Shakhtar Donetsk
Clubs in bold are the ones which have had some contact or allegations over his transfer to their club.
He wants to play, not to sit on the bench, right?
Chelsea is an option as they don't have a striker (yet) but Auba is very close. So, is Chelsea an option? Currently No.
Atletico is an option, but these stories have died down. Maybe there is sth going on and we are arranging a potential swap with their young striker or somebody else? Maybe.
Bayern is dead. No.
Napoli was interested, but they have Osimhen and Ronaldo would distrupt the perfect league start. Is ADL that stupid to still buy Ronaldo for fame? Yes. Would he start instead Osimhen? No.
Sporting has always been an option. If Ronaldo understands his days in the top flight are over and it's totally okay to score 30+ goals in Portugal, then this is a realistic transfer. He'll take a pay cut or wants to buy some shares in the club (or whatever, it's his boyhood club). Can it happen? Yes.
So, if Milik from Marseille goes to Juve, they need a striker. Do they have enough money to pay for his wages? No.
PSG would have been an option, but their new sporting director seems smart and he'd just be a surplus for this attack. If I were the owner of the club, I'd sign Ronaldo because then you can show the world that here's a team with to 21st century GOAT's. And that'd be a huge statement and outrageous marketability for the club. But director is smart. So, is it an option still? Maybe.
TLDR: We have some options and there are clubs that he'd be interested to play for, but wages or abundance of attacking quality would be an issue. So let's see, maybe we'll have a deadline day bomb ready for explosion.