Answer
TiCl4 + 2H2O -> TiO2 + 4HCl
Work Step by Step
TiCl4 + H2O -> TiO2 + HCl
First balance the Ti since it appears only once on each side. We have 1 on the left and 1 on the right so we are done.
Next comes the Cl since it also appears only once. We have 4 on the left and only 1 on the right so we need to multiply HCl by 4
TiCl4 + H2O -> TiO2 + 4HCl
Now we can move to the Hs and we have 4 on the right and only 2 on the left so we multiply H2O by 2.
TiCl4 + 2H2O -> TiO2 + 4HCl
Last we balance the Os and we have 2 on the left and 2 on the right so we are done.