The only way one can reach Sikkim is by passing through West Bengal. So you have to take a flight for Bagdogra from Hyderabad. From there you can hire a local taxi as it is just 120 kms from there.
For more - http:/www.indiatoursguide.org/sikkim/how-to-reach-sikkim.html
2-3 days
By train upto Nandyal and next by any road means.
three days
i would say 10 days
It depends upon the speed of the flight.
Sikkim's population is 607,688.
C.M of Sikkim: Pawan Chamling
Sikkim use the Indian Rupee.
it takes upto 8 to 9 hrs
international airport
The state is Sikkim - it has a population of 540,851, as per the census of 2001.
Sikkim is part of India.