Is the magnitude of buoyant force same in all liquids?

No. Buoyant force is equal to the weight of the displaced fluid.

B = mg

If ρ is the density of the fluid and V is the displaced volume:

B = ρVg

For fully submerged objects, where the displaced volume equals the volume of the object, buoyant force will be different in different fluids.

For floating objects, buoyant force equals the weight of the object, so it will be the same for any liquid that the object floats in.