It seems there is no Mahindra Ssangyong dealer ship in Lucknow, you can contact your dealership which is in your nearest city where can do book your car aswell. You can follow the site for know about the dealers in your city: http://www.cardekho.com/Mahindra_Ssangyong/cardealers
Mahindra Ssangyong Rexton RX7 comes with a 2 years or 1 lakh kms warranty and a 1 year extended warranty is optional. The car uses automatic gear gear box of Mercedes Benz. Repairing of this gear box included in the warranty along with some parts but the whole gear box will not be replaced.