FeCl3,SnCl2
FeCl2,SnCl2
FeCl3,Kl
HgCl2,SnCl2
The pair of compounds that can exist together is FeCl2, SnCl2. FeCl2 and SnCl2 (both are reducing agents and have lower oxidation no) Hence neither can reduce the other. The higher oxidation states include FeCl3, SnCl4.