I see only two options for Lukaku now:
- Staying at Chelsea
- Signing for Juventus after Vlahovic's leaving for PSG
There is no third option as it seems after hearing about Lukaku's turning down a big offer from Saudi Arabia. Inter is also not an option anymore as they have heard about Juventus' interest as well and decided not to go for him anymore. He should go to Juventus in this situation. Because he doesn't have a good past with Chelsea and I don't think it will change if he stays either.
I heard that Juventus fans rejected Lukaku from joining the team looks like there's a new drama

I still wonder how much of a role the fans play in making decisions for Juventus it really went out of their way. however Lukaku is more suitable to stay in the Italian League his ability can be relied upon there rather than going back to the Premier League so Juventus should suit him better if Inter are no longer interested.