What is the Maruti Nexa?
NEXA is Maruti's strategy to retail their premium cars. It's chain of showrooms that will specifically sell premium Marutis, starting from S-Cross crossover.

Maruti has never been successful in selling premium cars. It has forever been granted the cheap car-maker tag. The Grand Vitara, Kizashi, Baleno, SX4 have all been good products in their own right, but sold at a premium price right next to Alto, Wagon-R, 800 etc made them loose their sales. Because Maruti is recognized by those cheap cars. People therefore doubt the capabilities of a premium product by the Maruti brand. To shed such an image, Maruti planned to roll out a new set of dealerships with opulent interiors, smartly dressed executives and premium priced cars so that it can distinguish such cars from its cheap car portfolio. The dealership will only cater to cars which are priced higher, currently only S-Cross but in future expanding to more products.
It is Maruti's shot at premium car dealership. That's it.

Generally we have a perception that Maruti cars are aimed at the common people and they can't sell a premium sedan let alone the SUV. Kizashi and Grand Vitara are the prime examples of this.
People couldn't digest these cars coming from Maruti. Hence to change the perception and make the new Ciaz/S cross a running success, Maruti has decided to open a premium showroom to give the customers the feel of upmarket as well as rich experience.
It plans to sell S-cross only via Nexa showrooms and Ciaz via both the showrooms.

Will Maruti Suzuki's strategy of Nexa hamper its sales and benefit competitors like Hyundai?
Maruti Suzuki's major advantage is the early mover advantage. They were the first to bring an affordable, fuel efficient acr in India in 800 cc. One time they were having such a predominant share in passenger cars. Even now, they have almost 50 percent of the market share. So they have a critical mass, which no other manufacturer has, closely followed by Hyundai...