The most atmospheric place to dine in the city at night (weather permitting) is on a rooftop with a view of the temple goparums. In the city center your two best options are the pleasant Mogul Rooftop Barbeque Grill House at Royal Court, where a good meal will never break the bank (note however that no alcohol is served), or the equally good-value vegetarian restaurant Surya (where alcohol is served but no meat). Surya, within sight of Mogul, is located on the rooftop of the Hotel Supreme (entrance from West Perumal Masonry St.; exit the temple's West Gate and walk down Town Hall road, then turn right into West Perumal).
For a more fine-dining occasion, look no further than On Board, the elevated al fresco terrace at the Taj (not to be confused with The View, where cuisine standards are patchy). There is a very good set menu (predominantly tandoor-style kebabs), and it is only open at night, when the city sparkles at your feet. The menu is priced at Rs 1,500 (plus taxes) but is well worth the splurge for the atmosphere alone.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.