From what I have learned, the simplest model for predicting the polarizability of a molecule is to assume that polarizability scales with the type and number of atoms and the polarizability of these atoms, such that the polarizabilities of individual atoms are linearly additive.
How to predict the polarizability of a C atom and a H atom based on the data for methane and ethane.
(b): Predict the polarizability for a Cl atom based on your answer for part a and the data for carbon tetrachloride
(c): Based on the answers for parts a and b, predict the polarizabilities for CH3Cl, CH2Cl2.
This solution explains how to predict the polarizability of several molecules.