The electrode which has more reduction potential will get reduced in spontaneous reaction in the cell. So, spontaneous reaction will be
2Fe3+(aq)+2I−(aq)→2Fe2+(aq)+I2
Iron will act as cathode and Iodine will act as anode.
E0cell=(E0RP)C−(E0RP)A
=0.77−0.54
=0.23V
=23×10−2V