Real Madrid have no shows their interest to Vlahovic because they have Joselu and this player can be played as centre striker but i highly doubt Joselu quality will be equal to Benzema because although last season he was performing well with Espanyol but during his career Joselu only spend his time playing with mediocre teams so for centre striker Real Madrid have to look for other players and it's necessary because next season the competition will be so tight especially at champion league and Laliga
Their main interest is on Mbappe but Vlahovic is not a bad striker. He is very good and has many good skills including free kick but of course he does not have similar style and skills like Karim Benzema. With Vinicius and Rodrygo, it is not bad if Real Madrid buy Vlahovic and put him into the center of their attacking system.
Joselu is like an alternative player and not a main striker for Real Madrid. I believe that Real Madrid will look for another better striker in this summer and they still have time to complete a transfer to fill up that position.
About Mbappe although many media has been speculate he will be arrived to Real Madrid this summer but in fact so far they will be stick to their decision that this summer they wouldn't bought him and Real Madrid will gets Mbappe for season 2024 with free transfer status but transfer window deadline still a month remaining so everything still possible to happend and maybe Fiorentino Perez will change his mind and he will attempts to buy Mbappe soon
Mbappe does not show his best performance if he is used at the striker position so if Real Madrid buy Mbappe, they will plan to use him at swings if they already have a good striker. If they still lack of a striker, they will temporarily use Mbappe at that position but it won't last long and the player will not feel happy too.
With a clear announcement from PSG that they will not again increase salary and power of Mbappe in their club, just to expand the contract. Real Madrid will continue their negotiation with PSG and complete the transfer in this summer. Meanwhile they will look around for a good striker too but it is not their main priority in this summer.