Get inside a DTC bus to the Gurgaon Bus Stand....And then take a 'Rikshaw' to Shivaji Nagar........You'll find many standing outside the bus stand.
Or call 011-43434343 for Radio Taxi....They'll pick you from the Railway Station and leave you to the house where you want to go (call them in advance about this) in the Shivaji Nagar...
As simple as that......
I think that you're coming from a different place other than Delhi and you want to go to Gurgaon.