I am planning on arriving via train to Nizamuddin Station in Delhi. I need to get to the airport to catch a flight back to the US. How long will it take to get from the train station to the airport? Is there a prepaid taxi stand?

The other option is to take a train to Jaipur and fly from Jaipur, but I'd rather not do that since it wastes more of the day (and I'd have to catch the train at 10 AM instead of 1 PM).

I'm coming from Sawai Madhopur.

Thanks for advice!