$\mathrm{AgNO}_3$ solution is ionic in nature. It contains $\mathrm{Ag}^{+}$ ions which when react with $\mathrm{Cl}^{-}$ ions produce a white ppt. of AgCl. In $\mathrm{CCl}_4$ the Cl atoms are covalent in nature. They are not present as ions. Therefore, when $\mathrm{AgNO}_3$ is added it, it does not produce a white ppt. of AgCl.