Judgement passed against us what can we do

My friend bought a plot of land in 2004 and the same was duly registered and demarcated. However they could not take the adverse position of the property, As it was preoccupied by a person. The said person filed a suit against my friend for cancellation of sale deed which my friend challenged through counter claim. The judgement came after almost 11 years in favor of the opposite party which I think is totally biased denying nature justice to my friend. I therefore seek your expert advice on this matter .