Hi,
Indian Railways publishes Annual Statistical statements
http://www.indianrailways.gov.in/railwayboard/view_section.jsp?lang=0&id=0,1,304,366,554,1817,1822, in its 16 Zone level. There seems no usable GIS file on Railway zonal map, apart from a Wikipedia image
https://upload.wikimedia.org/wikipedia/commons/b/b1/Indianrailwayzones-numbered.png. This image was georeferenced, digitised and uploaded here
https://github.com/nishadhka/railways/blob/master/zones.json. Due to issues with the digitisation process, the quality of polygons needs to be improved. Requesting sharing of the original shape file if any available.
In search of this found following useful resources related to Indian Railways
1. Indian Railway Geoportal- An upcoming geoprotal
Regards,
Nishadh KA
Research Associate