  This is the second part of a three part series abut delocalization for band
matrices. In this paper, we consider a general class of $N\times N$ random band
matrices $H=(H_{ij})$ whose entries are centered random variables, independent
up to a symmetry constraint. We assume that the variances $\mathbb E
|H_{ij}|^2$ form a band matrix with typical band width $1\ll W\ll N$. We
consider the generalized resolvent of $H$ defined as $G(Z):=(H - Z)^{-1}$,
where $Z$ is a deterministic diagonal matrix such that $Z_{ij}=\left(z 1_{1\leq
i \leq W}+\widetilde z 1_{ i > W} \right) \delta_{ij}$, with two distinct
spectral parameters $z\in \mathbb C_+:=\{z\in \mathbb C:{\rm Im} z>0\}$ and
$\widetilde z\in \mathbb C_+\cup \mathbb R$. In this paper, we prove a sharp
bound for the local law of the generalized resolvent $G$ for $W\gg N^{3/4}$.
This bound is a key input for the proof of delocalization and bulk universality
of random band matrices in \cite{PartI}. Our proof depends on a fluctuations
averaging bound on certain averages of polynomials in the resolvent entries,
which will be proved in \cite{PartIII}.
