The proposal, which the government approved in August, was met with strong protests by the Opposition.
Mughalsarai station, constructed in 1862, is the largest marshalling yard in Asia.
Its renaming is being seen as an attempt by the Adityanath government to preserve BJP icon Deen Dayal's legacy.
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About Mughalsarai, India's fourth busiest railway station
Mughalsarai station on the Howrah-Delhi Grand Chord line is the fourth busiest station in India. The 12.5km-long station handles around 1,500 wagons daily. The biggest wagon repair workshop of the Railways is also located at Mughalsarai.
The link between Deen Dayal and Mughalsarai station
Deen Dayal, a close associate of the RSS, co-founded the Bharatiya Jana Sangh in 1951. It was eventually reborn as the BJP in 1980.
He was found dead at Mughalsarai in 1968. Some are skeptical about the reasons for his death.
The saffron party has celebrated Deen Dayal's life and philosophy since it came to power in 2014. Adityanath's win only boosted the drive.
Other places renamed in recent times
Apart from Mughalsarai station, UP's Farah town (where Deen Dayal was born) and a terminal at Agra's IAF airport will be named after him.
Mumbai's Chhatrapati Shivaji Terminus is now Chhatrapati Shivaji Maharaj Terminus. Elphinstone Road Station is Prabhadevi. The government has applied for renaming Oshiwara as Ram Mandir station.
The Bangalore railway station is nowadays called Krantivira Sangolli Rayanna after the freedom fighter.