Thank you to BHPian sameervg for providing this information. Heartfelt gratitude for sharing it with other enthusiasts!

Tata Motors has stopped selling all variants of the Nano except the GenX and eMax.

The GenX Nano, which was launched earlier this year, is available with a petrol engine only. It is powered by the same 624cc, 4-stroke, twin-cylinder engine as the old Nano. This engine produces 37 BHP and 51 Nm of torque. Transmission options include a 4-speed manual and a 5-speed automated manual transmission (AMT). According to dealers, there is a waiting period of two months for the AMT version. The demand for this version is very strong and AMT kits are in short supply.

The eMax, which can run on CNG and petrol, still uses the old Nano's bodyshell. It is powered by the same engine as the petrol Nano. However, while running on CNG, the unit produces 33 BHP and 45 Nm of torque. The engine is mated to a 4-speed manual transmission. The eMax is not available with an AMT.

The Nano is produced at the Tata Motors plant in Sanand, Gujarat.

Tata Motors has been trying very hard to re-position the Nano time and again. It hasn't been an easy task to change the way people perceived the Nano and boost its sales. But that hasn't stopped them from trying.

In an article by Motorbeam, it is mentioned that Tata will extend the Nano Twist range by introducing a new variant and will continue selling the E-Max (CNG variant). This means that it will axe the other two outgoing variants from December, 2014 - CX and LX. The CX will be replaced by a new XE variant which will come with additional kit such as a power steering, a bigger size steering wheel and new instrument cluster with an MID (which displays average fuel economy, distance to empty, trip meter, digital clock). The XE will now be available in 3 colours - Meteor Silver, Royal Gold and Serene White. The price of the XE is expected to be higher than the outgoing CX variant.

The Twist XT (top variant) will continue to sell as is. It comes with all bells and whistles - front power windows, keyless entry, central locking, music system with USB, AUX and bluetooth with 4 speakers, etc.

After numerous refreshes and price cuts, the Tata Nano is yet to find traction at the hustings. This has prompted Tata Motors to go in for an all new strategy to sell the car. From being the world's least priced car seeking to put India on four wheels, the Tata Nano will now see a major re-branding that could take the car higher up the value chain. The re-branding exercise will see the Nano being pitched at the youth, as a "smart city car". 

To make the car more appealing to this car buyer demography, who value convenience, style and fuel efficiency, Tata Motors plans to add more features to the Nano. The power steering, a long missing feature that buyers have been demanding, is likely to make the cut during the revamp. Mr Cyrus Mistry, the Chairman of Tata Motors,  made a mention of this to share holders during the company's 68th annual general meeting. The other feature to be added to the revamped Nano is the open-able hatch lid. 

In fact, test mules of the diesel powered Nano have clearly showcased the presence of a conventional hatch lid on the car. The Nano, in diesel guise, also gets new front and rear bumpers, and a re-routed exhaust. The car will be powered by a 800cc turbo diesel engine that is expected to output about 40 Bhp. The big selling point of the Tata Nano Diesel will be its fuel efficiency, touted to be well north of 35 Kmpl. The revamped Nano will get styling upgrades on the outside, to make it look more appealing. 

Tata Motors will also launch the much-delayed CNG variant of the hatchback. After being showcased at the 2012 Indian Auto Expo, the CNG powered Nano, dubbed the E-MAX, was unveiled earlier this year, during Tata Motors Horizonext strategy showcase. The CNG powered Nano will offer diesel-like running costs at a price that's marginally higher than that of a petrol powered Nano. The Nano CNG is expected to be launched within the next couple of months.