There are 3 lounges:

Terminal: MAA - International
Lounge Name: Maharaja Lounge
Access thru: F and J classes on AI/IC and for a few other airlines (eg TG)
Lounge Facilities: Hot and cold food buffet, bar, wifi, No showers etc

Terminal: MAA - International
Lounge Name: Clipper Lounge
Access thru: F and J classes on most airlines; Priority Pass (charges may apply), JP Amex, JP ICICI, Mastercard (specific card types only)
Lounge Facilities: Hot and cold food buffet, bar, wifi, No showers etc

Terminal: MAA - International
Lounge Name: Le Meridien (Royal) Lounge
Access thru: F and J classes on many but not most/all airlines (eg TG); Priority Pass (charges may apply),
Lounge Facilities: Hot and cold food buffet, bar, wifi, No showers etc

*Wifi is free for a short duration (30 mins, IIRC), but signal strength can be quite bad.

Also, most airlines provide a lounge pass that can be used either at the Le Meridien or Clipper Lounge. I would recommend Clipper - the other can be quite cramped, and service levels are better at Clipper. But the coffee in the Maharaja Lounge is, comparatively speaking, excellent !