Asin and Navya Nair stand out from the crowd of Malayali heroines who have flocked the Tamil film industry. It is nothing to do with acting skills, glamour or date issues or anything that you are currently thinking about. It is the address for communication.
These days, if you want to send a letter of appreciation to Asin or Navya you have to mail it to Chennai. This is because they are currently residing in Chennai in houses of their own. Looks like they are really keen to become an integral part of the industry. It also makes things easier for the directors or producers who have to discuss things with them.
On the other hand, the other heroines from Kerala like Meera Jasmine, Nayanthara, Banu and others still reside in Kerala. Banu is just one movie old, but Meera and Nayanthara have been around for quite a few years. They arrive for their shooting schedules, stay in hotels for the entire duration and go back to Kerala. It might just be sentimental attachment to their native places or some other reasons that make them stay back in Kerala. But one cannot deny the fact that staying in Chennai does have certain advantages; look at where Asin's career is at the moment.