fraud for property

Ex-party decree obtained for plot vb 64 b with boundaries vb 64 and vb 64a same boundaries given in their sale deed ..shown decree executed.filled case against. My father under section 6 of specific relief act but boundaries given now as wz 218 b and wz 213 a same as ours plot A47 and got decree .to stop that decree execution my father tried very hard but this question of change of numbers was never raised and opposite party was given posset ion of our house.suit for declaration was filled by my mother but primarily issues of limitation and res judacata are framed as my father has filed suit for same and withdrawn. I know fraud was played by putting different numbers. What can I do know or what should I do