There is no definite target from Real Madrid yet, but based on the news I've read, Madrid will be eyeing Pau Torres. a young players, but have a potential, of course this is very good for Real Madrid as they look for a long-term defender option as a replacement for Sergio Ramos. However, there is no further news regarding this rumor.
The even bigger news is that there is a talk about Varane possibly leaving, it is not sure yet and Real is trying to keep him at all costs because they do not want to lose two defenders at the same off-season which would make things harder, but Varane does want out, that much is known, yet he can't just walk out considering he needs to find another team to get him.
On the rebound of Ramos deal, Real Madrid is in talks with Leicester, the biggest talk is Wesley Fofana, that is what people are expecting to come out as big news soon, but we just know for sure they are in talks with Leicester it is that much, by all means it could be for any player in Leicester, but we all know they need a defender so it is either Fofana 90% chance, or there is a chance they may go big and buy Caglar Soyuncu who has been amazing at Leicester for few seasons now and worths around the same as Fofana. We also know they got Alaba as well, so that is not a bad deal already.