ancestral property and declaration suit for sale property

A:father B:first wife(died),child(first wife):1,2,3,4-females married,5-male married c:second wife,child(second wife):6,7- males married. TOTAL CHILD: four females,three males. PROPERTY: EIGHT ACRES OF LAND ISSUE: TWO CASES ARE RUNNING PARALLEL IN THIS FAMILY MEMBERS. FIRST CASE:- plantiffs-1,2,3,4&5 filed a suit based on ancestral property provision and claiming for five shares.defendants are "A",6&7 in the year 2011.due to the some reasons the defendants"A",5&6 did not attend the case and plaintiffs got preliminary decree in 2013 and they filed for final A:died on 2015 and 6 and 7 became expartie. still case is running. SECOND CASE:- when the above case launched "A": filed a declaration suit for entire property by mentioning that the property is not ancestral property and he get this property from this father(first owner)(grand father to 1,2,3,4,5,6,7) through unregistered will (1978). the defendants are; 1,2,3,4,5,6,7. while the case is going plaintiff "A" sold his property to defendants 6&7 (six acres of land) through sale deed because of having debts and health problem.due to health problem plaintiff "A" did not attend the court and court appointed a commissioner but due to serious ill he was unable to file his argument. in the year jan-2015 plaintiff "A" died and his second wife-"C"(mother of 6,7) furnished information regd: death of his husband and become plaintiff( in the place of plaintiff "A".) still case is running. required your valuable advice: 1) how to stop the first case not to go for final decree,please advice "C", 6 and 7 ? 2) in the second case the lawyer advised defendants 6 and 7 to file a declaration suit to protect their purchased property from plaintiff "C” defendants 1,2,3,4,5 . is declaration is necessary or not .what are the steps require to 6 and 7 to protect their purchased land ? 3) is there any provision to stop the first case judgement by linking it with the second case. respected lawyers and superiors please provide your valuable in this case 7- represents me.for convenience i have represented the family members as numbers and alphabets. presently i am pursuing law(final year). dear superiors and seniors i will require your valuable advices and feedback. my heartful thanks to all lawyers who are sparing their valuable time for my case,thank you.