Can a gpa holder file a case regarding property.

Whether the attorney has been authorised to represent the executant of the PoA ?

No sir, advocate have not been appointment yet for the case. The property owner is a senior citizen having some health issues, so he had already given GPA to collect rent, represent govt departments and also represent in various courts to one of his family member. So can that person file a case by appointing a advocate regarding the same? Will High court give weightage to GPA holder? Or if the actual owner appears in court is more beneficial for case? 

Whether GPA gives such powers and authority to represent or file cases stating such property etc. ?   Finally the case should be filed through an advocate, and get clarification from a local advocate on your such authority and powers.  It may not be always necessary for each and every party to appear in court except for deposing/cross-examination as a witness.  A specific attorney can also be given after filing the suit in his name mentioning such suit name, court name.  POA can also be a witness to the extent of relevant facts known to him in the issues framed.

Yes GPA can ,he has right.

The GPA can, if he is so authorised.