Hello Kaushal !!

Your son will be eligible for the state quota of the state for which he has the domicile.

For Maharashtra, he should be residing there for 15 years or complete 10th and 12th , hence not eligible.

For Gujarat  and Rajasthan one should be residing there for 10 years , hence not eligible for these two states .

Therefore, he has to apply through All India Quota only. 

All the best .

Hope this helps .