To simplify the expression \((6^2)^4\) using the Power Rule of Exponents, you multiply the exponents. The Power Rule states that \((a^m)^n = a^{m \cdot n}\).
Applying this to our expression:
\[ (6^2)^4 = 6^{2 \cdot 4} = 6^8 \]
So, the simplified expression is:
\[ 6^8 \]