Complex Numbers and Quadratic Equations: JEE Main 2026 Mathematics question

Let the circles $C_1: |z|=r$ and $C_2: |z-3-4i|=5$, $z\in\mathbb{C}$, be such that $C_2$ lies within $C_1$. If $z_1$ moves on $C_1$, $z_2$ moves on $C_2$ and $\min|z_1-z_2|=2$, then $\max|z_1-z_2|$ is equal to :