(2) Is it right to give food especially on death anniversary (barsee) every year, having intension of isal-e-sawab?
بسم الله الرحمن الرحيم
(1) Yes, it is lawful and shall earn reward. Any dish whether Biryani or something else whether it was favourite dish of the deceased person or not whatsoever food you would feed to the poor and needy ones with the intention of sending reward to the deceased’s soul its reward shall go to the person.
(2) No, you should feed them without following the customs of tija, daswan, chaliswan and barsi as these crept into Muslims from Hindus.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.