Originally Posted by Aeran

You should be fine doing an international transit through DEL via the transfer desk without going through customs / immigration, however plan on having a really horrible experience doing it.

Just did two international transits through DEL in the last month (SQ F -> TG J; TG J -> SQ F) and each took at least 1.5 - 2 hours. Essentially you go to a crowded transit desk (which doesn't have any signs/areas for airlines) and all the agents will be on their cell phones assisting the hordes of other folks trying to transfer. You'll try and get someone's attention but need to get lucky as only the agent that handles the airline you arrived on will help you (again, no labels so you just have to keep asking). Once you find the agent, they'll take out a piece of paper (I didn't see anyone use a computer) and take down your arriving flight #, departing flight #, luggage slip #(s), passport number, and name. Then they'll proceed to make about 20 calls on their mobile while you sit to one side for about 1-2 hours and if they don't forget you (check every 20-30 mins just to make sure) you'll get a boarding pass. Then you can proceed through security and into the departure hall. May just be my experiences, but I say don't plan a short connection to be on the safe side.

I imagine if you are able to get a boarding pass issued at the country of departure you'll be able to skip the worst part of it.