Hello Mr. Gupta,
Tata Nano LX and Tata Nano LX SE are not the same variants, instead Tata Nano LX SE was a limited edition version of Tata Nano LX. This special edition LX SE comes equipped with several new additons such as alloy wheels, music system with USB compatibility, glove boxes etc. All the accessories come factory fitted. The Limited edition Tata Nano was launched on 25th October, 2012 and since its a limited edition so its not available now. And yes, a Tata Nano manufactured in Oct'12 can be a SE model. To get more information on the same, Kindly visit the link below: -
New Tata Nano with EasyShift is available at Rs. 2 lac (Ex-showroom, Delhi), and the final cost depends on the valuation of your car. So, first get the valuation of your car from authorized Tata dealer, so he can give you a final quote for the new car.