House Possession

If the decision of the higher Court is adverse, you have to vacate the premises. In the unfortunate event of the demise of your parents during the pendency of the case you can be a party to the case as a legal heir. You can not file a fresh case if after the death of your parents. The decision of the Higher Court in the ongoing case is legally binding. 

Yes, once you get impleaded as the legal heir., you can continue residence so long as the case is pending, even after your parents' lifetime

In what capacity your father/ family is holding possession such as tenant / succession / relative etc. ? 

What is the order / judgement passed against your father, which is stated to have been challanged ? 

The facts posted by you suggest that your case is, prima facie,  very weak since the Trustees [owner] do not want your father / parents/ family to continue possession.

What is the opinion and advise of the lawyer engaged by your father as s/ he [lawyer] is well aware about facts and circumstances of the case and an able, competent and intelligent enough to satisfy your queries ?

NOBODY CAN GET FROM THIS PROPERTY IF YOU ARE LIVING IN MORE THAN 12 YEAR