Answer
$9.4mol\ TiCl_{4}$
Work Step by Step
$\frac{12.4mol\ TiCl_{4}}{1}= 12.4mol$
$\frac{18.8mol\ Cl_{2}}{2}= 9.4$
As can be seen $Cl_{2}$ is the limiting reagent so:
$18.8mol\ Cl_{2}\times\frac{1mol\ TiCl_{4}}{2mol\ Cl_{2}}= 9.4mol\ TiCl_{4}$