The compound with the formula Sn(SO3)2 is called Tin(II) Sulfite.
In this compound, the cation is Tin (Sn) and it has a +2 oxidation state, which is indicated by the Roman numeral II in the name. The anion is Sulfite (SO3) with a -2 charge. The formula Sn(SO3)2 indicates that for every one tin cation, there are two sulfite anions, balancing the overall charge of the compound.