The Alliance Members are classified into 6 Ranks: R0, R1, R2, R3, R4, and R5. Different Ranks have different privileges. You can go to Alliance - Members, and then tap the “!” button in the upper right corner to check more details.
*R3 or above members can promote or demote other members who are at least 1 rank lower than them.
*R4 or above members can kick out other members who are at least 1 rank lower than them.