It's very likely that Mbappe will leave the reigning Ligue 1 Champions after PSG's chief executive, Nasser Al-khalifi publicly declared that if Mbappe doesn't sign a contract extension, he would be sold.
Real Madrid are known to be long term admirers of Mbappe, and it's even rumored that Mbappe already has an agreement with Los Galacticos to join them next summer after his current deal with PSG expires.
However, one thing is for sure, if PSG decides to sell Mbappe, then he won't come cheap, so Real Madrid will have to come up with a substantial offer to land their man.