Challenging the order/Judgement of the appellate court

The trial court had acquitted the accused from the charges of section 384 &387 IPC levelled against him. Against the order of the acquittal the informant filed an appeal under section 372 CrPC. Now the appellate court has allowed the appeal and pronounced it's Judgment in favour of the appellant. I being the respondent no.2 looking forward to challenge the impugned order of the appellate court. What should I do..?