you should look at bookings

xnarun

Well you should look at bookings atleast for the trunk routes if you intend making long railway journeys - you see December is christmas vacations in schools so getting tickets could just be that much dicey.

I would suggest you log on to www.indianrail.gov.in and go to the Train accomodation/fare tab -key in your destination and origin points and see how the status of the tickets is currently.

with children i am not very sure if the the unreserved coaches would be comfy.

Cars are a good though rather pricey option. on some other thread i saw some recommendations for taxi operators.

you may want to look at buses - tamil nadu and kerala (since you talk about the south) have good options

Hope you have fun