Yes. Well electrification involves a lot of factors, like setting up of TSS (Traction Sub Station), getting a feeder line of 132Kv from state board, which railways step it down to 25Kv with their own transformers. The Voltage varies between 19Kv min to 27Kv max. Then setting up of neutral sections. So, for all this to work well, railways do site survey as to from which section to get feeder line from PSPCL etc.
When some sections get completed, RE energise/charge the lines with 2.2Kv to prevent theft of OHE equipments etc. until the whole section is complete for full energisation of 25Kv.