A body is acted upon by two unequal forces in opposite directions, but not in one line. The effect is that the body will have:

Let the two unequal forces acting on the body be ${\vec{F}}_1$ and ${\vec{F}}_2$ such that $|{\vec{F}}_1|\ne |{\vec{F}}_2|$.
1. Translational Motion: Because the forces act in opposite directions and are unequal, the net external force ${\vec{F}}_{\text{net}}={\vec{F}}_1+{\vec{F}}_2\ne 0$. A non-zero net force causes linear acceleration of the body's center of mass, resulting in translational motion.
2. Rotational Motion: Because the forces do not act along the same line of action, their lines of action are separated by a perpendicular distance. This creates a net torque (${\vec{\tau }}_{\text{net}}\ne 0$) about the center of mass, causing angular acceleration and resulting in rotational motion.
Therefore, the body will exhibit both translational and rotational motion.