Answer
(Fatwa: 724/544=L/1430)
It is unlawful for the boy and girl at the time of engagement to sit on stage and receive gifts from the relatives. Your brother is right to oppose your father. By disobeying Shariah one cannot get honour and prestige, rather it will end up ultimately in loss and humiliation. The Prophet (صلی اللہ علیہ وسلم) has prophesied in hadith that people will start loving the sin and hating the righteousness, so at this juncture of time one will be counted among the pious slave of Allah who will recognize the righteousness and follow it and will find out the sin and shun it. Hadhrat Thanwi in his books has regarded one who refrains from customs and un-Islamic traditions as the wali and beloved slave of Allah. Therefore, your brother should oppose it and not be ready for the same.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband