We are asked to evaluate $\log_{6} 216 \sqrt{6}$.
First, we note that $216 = 6^{3}$. This is because $6^{3} = 6 \times 6 \times 6 = 216$.
Also, $\sqrt{6} = 6^{1/2}$.
Therefore:
\[
216 \sqrt{6} = 6^{3} \times 6^{1/2} = 6^{3 + 1/2} = 6^{7/2}
\]
Now:
\[
\log_{6} (6^{7/2}) = \frac{7}{2} \log_{6} 6
\]
Since $\log_{6} 6 = 1$, we have:
\[
\log_{6} (6^{7/2}) = \frac{7}{2}
\]
Hence, the value is $\frac{7}{2}$.