Clarification on property purchase

Hi Sir, Have the following query on property purchase in Bangalore. Details: *The seller got the property through a gift deed from her father. *The father has 1 son and 1 daughter. *Daughter is now the seller and is unmarried . But her brother has not signed the Gift deed given to her as a witness or anywhere else. *The gift deed was executed 3 yrs ago. *The father got this property allotted to him from BDA which is the city developing authority 14yrs ago. *The father and daughter(seller) will come for the property registration. Now the seller's brother is not available for the property registration as a witness since he is located in a different city . He is not ready to come for the registration as he is busy. Questions: 1. Is it really necessary to get the brother's signature as a witness while purchasing this property ? 2. Can the brother start any legal dispute in future with respect to this property ? 3. Is it safer to buy the property without the brother's signature ? 4. What other precautions to be taken care if any ? Kindly clarify. Thank you.