The Balance equation is as follow,
                2 Al + 3 FeSO₄ → Al₂(SO₄)₃ + 3 Fe
Oxidation Number of elements in reactants,
          Â
               Al = 0
              Fe = +2
             SO₄  = -2
Oxidation Number of elements in products,
          Â
               Al = =3
              Fe = 0
             SO₄  = -2
Result:
     As the oxidation state of Al has changed from 0 to +3, means it has lost 3 electrons so it is oxidized.
     And the oxidation state of Fe has changed from +2 to 0, so it has gained 2 electrons, hence it is reduced.