First of all, think of these molecules in terms of their respective parts (aka ions).
Ca(2+) SO3(2-) + NH2(+1) Cl(-1) =>
// not really sure about charge for NH2 ion but assume it is +1 to balance out Chlorine
Now, what do you think the products are going to be? It should be a substitution reaction:
Substitution= AB+ CD => AD+BC
Therefore CaSO3 + NH2Cl => CaCl + NH2SO3
Ill leave it to you to balance the equation