Oh, then you should be fine. 9W are good at checking luggage through in my experience (even to other carriers), then you are free to use the international connections channel, which will take you straight to emigration and security, well before 3 hours in advance.

That said, personally, with a connection that long, I'd be tempted to jump on the metro and head into the city for something late to eat - depends how comfortable you would be doing so with relatively limited time. Catch the lastish metro back and then you're good to go. If you do want to do this, do *not* follow the connections channel as there is no way out.

The international terminal at DEL is pleasant enough - plenty shops and cafés, if that's your thing, and some fairly acceptable lounges. I'd struggle to recommend spending any significant town there, though.