The dimension of torque is

We define torque about an axis of rotation is equal to the product of the magnitude of the force (F) and the perpendicular distance (r) of the line of action of force from the axis of rotation.

$\Rightarrow \mathrm{\tau }=\mathrm{F}\times \mathrm{r}$

 Dimensional formula of torque = Dimensional formula of force x Dimensional formula of distance = 

$\left[{\mathrm{MLT}}^{-2}\right]\times \left[\mathrm{L}\right]=\left[{\mathrm{ML}}^2{\mathrm{T}}^{-2}\right]$