The problem asks us to find the value of $y$ for the function $y = -\frac{1}{3}x^2 + 3$ when $x = 6$.

1. Problem Description

The problem asks us to find the value of $y$ for the function $y = -\frac{1}{3}x^2 + 3$ when $x = 6$.

2. Solution Steps

We are given the function $y = -\frac{1}{3}x^2 + 3$.

We are given that $x = 6$.

We need to substitute $x = 6$ into the equation and solve for $y$.

$y = -\frac{1}{3}(6)^2 + 3$

$y = -\frac{1}{3}(36) + 3$

$y = -12 + 3$

$y = -9$

3. Final Answer

The final answer is -

9.