You will be eligible to enter Air India lounge, where is left side intended for business class and small right side for first class passengers, that’s the only difference. The buffet is located in business class part of the lounge and you should get a waiter who will bring you any drink you want from the bar, which is also located in business class part of the lounge. There are showers and sleep rooms available. The Air India lounge is not definitely the top notch, neither the food selection.
The Encalm lounge has better food selection, but can be very, very crowded.
I would prefer to spend more calmed time in Air India and wait for great LX first class dining.