I have a step down transformer 600V to 3phase 220
On secondary I am getting L1 to G 200V L2 to G 200V and L3 to G 356V
But from phase to phase I am getting 220V
Any one with any suggestions?

Give the vector groups(star or delta) of both windings & whether neutral is floating or earthed,type load(1phase or 3phase etc)