You will get taxi from Airport at 300-500
There is a pre paid counter at the airport.. Rs 2070 approx till Deorali Taxi Stand,add Rs 300 for hotel drop.So if you get a cab within Rs 2500 it's a good rate.
Sometimes you get cheaper from touts outside in the parking lot esp for Sikkim registered vehicles
Siliguri Jn and NJP are two different railway station 10 km apart.You would mostly get sumo/balero/maxx for share transport (driver +2+4+4),baggage goes on top of the vehicle.They would drop at Deorali taxi stand,few Km before MG road.You can get small cab to your hotel.Edited: 19 February 2017, 03:07
Shared vehicles are available outside Njp- just don't fall prey to touts (lots of them out there). Shared vehicle will drop you mostly to Deorali Taxi Stand,10 mins drive from MG Marg.