Adithyavr
There are are a few Api's which are available for free

1) http://trak.in/tags/business/2014/09/26/...
2) http://www.railwayapi.com/pricing/
3) http://pnrapi.dfth.in/

PS: I am interested to try and core for this API. Can you point out steps for that?
posted by Adithyavr 4 years and 13 days ago Link

ScreapDK
Thanks for the source-links!
Here's a guide to get you start developing these Instant Answers:
http://duckduckhack.com/
posted by ScreapDK Community Leader4 years and 12 days ago Link
jee1mr
Hey, Are you still working on it?
posted by jee1mr 4 years and 8 days ago Link
Adithyavr
I have started working this week. Will take some time to learn the engines itself.
posted by Adithyavr 3 years and 11 months ago Link