Question

What is the reactant for Na + SnCl4 -> Metal + Salt?

Answer 1

reactants are found on the left-hand side of the arrow, you've already listed the reactants as Na and SnCl4. If you mean to ask what the products are, I'd ask you first:

Do you know the 5 classes of reactions?

Answer 2

metal displacement reaction ( redox) reaction where one of metal atom get converted into ion and another ion get converted into metal atom based on their electrochemical redox potential in the followin case