If you are willing to travel to New Delhi Airport (international or domestic) from any part of Delhi, there are multiple ways to reach. But reaching in time in peak hours is probably the biggest hurdle, because of the huge traffic clog on the roads.
So an easy way can be to travel via the Delhi metro. Irrespective to which type of airport you want to go, domestic or international, first, try to locate the nearest metro station from your location and then travel to a station called Rajiv Chowk. Next, you have to change train (metro) and take a train towards the station Jahangir Puri. After boarding from Rajiv Chowk, by metro rail towards Jahangir Puri, the next station will be New Delhi, where you will have to change train again. At New Delhi, metro station you may look or ask for Airport Express metro services which directly takes passengers to International airport of Delhi (the stop is called IGI Airport).
If you are willing to travel to domestic airport you need to follow the same path except that you have to deboard from the train at a station called Delhi Aerocity which is a station before IGI airport. Once you reach Delhi Aerocity, you can find shuttle bus services on the station premises, which will take you to the domestic terminal.
Since, Metro rail don’t face any traffic like in the roads, in my opinion and experience it’s the best mode of travel to the domestic and international airports of Delhi.
A common problem you may face in Delhi metro is to decide which metro-line to choose, since they have different metro routes like blue line, yellow line etc. There are maps available which nicely show these lines and one can obviously follow this. But if you are, in short of time and lack the patience to decode those maps an easy way is to ask the metro staff and the other passengers whom you meet on the metro rails and stations. But I found a drawback of asking others about the route, few people deliberately by fashion or by passion prefer to show the wrong direction when asked and many others too experienced such. So its good to ask more than one individual to verify if the info shared by one is correct or not.
Hope this brief guideline will help you to reach the Delhi international or domestic airport easily.The above writing is based on the individual experiences of the author, which might not be totally correct. So cross check the travel info from other resources too. Thanks.