Jaipur Airport to Jaipur Railway Station is about Kms 17 and Jaipur airport to Ajmer by road is Kms 135.The taxi people they will charge for both side up and down this is the system in all over India.Train and Buses Fly get they will charge for one side.You can find some travel counters on the Airport and give him your travel details.What kind car you need A/C or Non A/C the price depend your choice.On the airport you can find pre paid taxi in fixed price.