Think ! It is Complex

One thing you should remember is that $\sqrt{a} \times \sqrt{b} = \sqrt{ab}$ is valid only when $a \geq 0, b \geq 0$ .

$\sqrt{-3} \times \sqrt{-2} = \sqrt{3} {\color{teal}\sqrt{-1}} \times \sqrt{2} {\color{teal}\sqrt{-1}} = \sqrt{3}{\color{teal}i} \times \sqrt{2}{\color{teal}i} = \sqrt{6}{\color{teal}i^2} \quad (\text{Here } i^2 = -1)$

$\large \boxed{{\color{#3D99F6}\sqrt{-3}} \times {\color{#E81990}\sqrt{-2}} = \color{#20A900} - \sqrt{6}}$

$\sqrt{-3}\times \sqrt{-2} = \sqrt{-1} \times \sqrt 3 \times \sqrt{-1} \times \sqrt 2 = {\color{#3D99F6}(\sqrt {-1})^2} \times \sqrt {2\times3} = {\color{#3D99F6}- 1} \times \sqrt 6 = \boxed {-\sqrt 6}$