For a 4f- orbital, $n=4$ and $1=3$
For a given value of $l$, there can be $(2 l+1)$ values of $\mathrm{m}_l$ ranging from $-l$ to $+l$.
Thus, $\mathrm{m}_l=+1$ is possible.
$
\mathrm{m}_{\mathrm{s}} \text { can be }+\frac{1}{2} \text { or }-\frac{1}{2}
$