Free WiFi only lasts 2 hours, many restaurants refuse to accept credit cards. No way to get rupees airside. No outlets. The Jet Airways lounge will sell you a day pass for INR750.
Here's my tip, avoid this place like the plague. It's disorganized, officious, dirty and there are as many security, baggage, boarding pass, and passport checks as there are passengers.
Do not try to arrive more than 3 hours before!!! We have the flight at 3am (already that sucks) and they do not allow you to go inside. You have to go to the horrible waiting Room and pay 60 rupiees