Step 1: Recall the section formula.
If a point \(P(x, y)\) divides the line joining \(A(x_1, y_1)\) and \(B(x_2, y_2)\) in the ratio \(m:n\), then
\[
(x, y) = \left( \frac{mx_2 + nx_1}{m + n}, \frac{my_2 + ny_1}{m + n} \right)
\]
Step 2: Substitute the coordinates.
\[
x = -4, \; y = 6, \; A(-6, 10), \; B(3, -8)
\]
Substitute in the formula:
\[
-4 = \frac{m(3) + n(-6)}{m + n}, \quad 6 = \frac{m(-8) + n(10)}{m + n}
\]
Step 3: Simplify the first equation.
\[
-4(m + n) = 3m - 6n \Rightarrow -4m - 4n = 3m - 6n
\]
\[
-7m = -2n \Rightarrow \frac{m}{n} = \frac{2}{7}
\]
Step 4: Verification using the second equation.
\[
6(m + n) = -8m + 10n \Rightarrow 6m + 6n = -8m + 10n
\]
\[
14m = 4n \Rightarrow \frac{m}{n} = \frac{2}{7}
\]
Step 5: Conclusion.
Hence, the point \((-4, 6)\) divides the line segment joining \(A\) and \(B\) in the ratio
\[
\boxed{2 : 7}
\]