The distance between two points \( (x_1, y_1) \) and \( (x_2, y_2) \) is given by the distance formula:
\[
d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}
\]
Substituting the given points \( (1, -3) \) and \( (4, -6) \):
\[
d = \sqrt{(4 - 1)^2 + (-6 - (-3))^2}
\]
Simplifying the equation:
\[
d = \sqrt{(3)^2 + (-3)^2} = \sqrt{9 + 9} = \sqrt{18}
\]
Finally, simplifying \( \sqrt{18} \), we get:
\[
d = 3\sqrt{2}
\]