Undoubtedly Goa and Andaman are the best choices for a beach vacation in India. But I believe that a vacation in Goa is not worth it as the place is too much overcrowded. On the other hand Andaman far more beautiful less crowded and unexplored. The islands have a tropical climate. The North-East Monsoon comes in Andaman in month of November. So there is no fury of chilling winter in December, no water clogging or traffic jams. For those who want to enjoy boating, swimming, snorkeling, sightseeing Andaman is best place for them.
Hi Geetanshu, Both are Goa and Andaman is a good option in December its your choice. Attached below with my comments you can see few packages offered by Tripoto for hassle free travelling. Please take a look, fill the form and someone will get in touch with you. Thanks!