Property dispute

Dear sir/madam I am from Andhra Pradesh. My grandfather's are 3 (A,B and C) brothers and all are died. Among them B was purchased some properties by his own. He wrote an unregistered "WILL" in favour of his brother 'A' in the year of 1970 after the death of his wife and childrens. After the death of 'B' the properties was enjoying by 'A'. In and around the year of 1980 the brothers A & C were died. After that till now legal heirs of 'A' were enjoying and selling the properties. Now the grandson of 'C' is asking share in that property. Now my queries are 1) unregistered WILL is valid or not because the testator and two witnesses of the "WILL" are no more. 2) Is the grandson of 'C' is having rights to be asking share 3)He is having the political influence and blackmailing with us for share 4) How to prove the WILL. 5) we came to know that he created the duplicate WILL. 6) is it possible to find the originality of WILL. 7) We approached to legal advocate for getting injunction temporarily and permanently. But the advocate told the present judge is giving temporary injunction depends on merits that too after hearings of both the parties, it may take years. Kindly give some suggestions.