These three mainline stations, the Moscow terminals for trains from Tallinn, Helsinki, Central Asia, Trans-Siberian services from Vladivostok and Beijing, and nearly all trains from St. Petersburg, are situated on Komsomolskaya Ploshchad, a little over 20 km from the Iris Congress Hotel.
By taxi
If you plan to negotiate a taxi on arrival, you should not pay more than $50 for the trip to the Iris Congress Hotel. However, it may be easier to book a transfer with a driver to meet you off the train, which you can do here. The drive to the hotel should take a little under an hour.
By metro
Komsomolskaya Metro Station is connected to all three stations. Take the brown circle line and travel counterclockwise two stops to Novoslobodskaya. Change there to the grey line and head north four stops to Petrovsko-Razumskaya, which is a 25-minute walk from the Iris Congress Hotel. You can also take bus number 656 from the metro station directly to the hotel.