This is the 14367th most frequent Turkish word.
olurlarsa
"If they become."
'Olurlarsa' is used in a conditional sense, implying 'if they become'. It connects a possibility (becoming successful) to a resulting action (celebration).
Başarılı olurlarsa, kutlama yapacağız.
If they become successful, we will celebrate.
Here, 'olurlarsa' implies the condition of becoming friends, linking to a consequent emotional state of happiness.
Arkadaş olurlarsa, daha mutlu olacaklar.
If they become friends, they will be happier.
In this case, 'olurlarsa' conveys the condition of taking a role (becoming leaders) and its consequence (leading the project).