Khatha Transfer

Hi, My grandfather passed away recently in 2020. He has written WILL in a normal A4 sheet paper and two witnesses (1 of them passed away and other is still alive) have signed back in 1998. According to this will, he has shared his self acquired BBMP house equally among two of his sons - my father and his brother. He has clearly mentioned that none of his daughters are eligible for any of his assets. We are Hindu family. Question 1 - Is this still legal document as someone told me that it should have been registered on a stamp paper or attested by gazetted officer? Question 2 - My uncle is willing to give up his share of this house property entirely to my father. What is the procedure for this during Khatha transfer? Is his physical presence required as he is settled in abroad and unwilling to travel due to covid scare? Question 3 - He had another plot of land under his name. He has not mentioned about this property in the will. However, it was purchased before writing the will in 1998. Only thing he has clearly written is that - "None of his daughters are eligible for any of his property" (exact same words). So who are eligible candidates for this property? If my father wants to get it transferred to his name as sole owner, then what is the procedure?