Axia and Wigo are same cars with different badges Wigo may have better resale value cause of the toyota badge.
Alto is a very basic car, RS has some more features, if you need better interior i would rather go for WagonR. Also compared to other similar type cars, WagonR is very common and in future it would be easy to get parts and so on. Compared to your current indian alto, spare part prices could be higher as for now. If you are concern with that you can go for Axia or Wigo