Is Pind Daan at Brahmakapal effective for ancestors who died unnatural or untimely deaths?

Yes, Brahmakapal is considered exceptionally potent for performing Pind Daan and Shraddha for ancestors who suffered Akal Mrityu (untimely/unnatural death) or whose souls may be trapped or restless (in Pretayoni). The profound sanctity of Brahmakapal, blessed by Brahma and Shiva, is believed to grant immediate peace, liberation from suffering, and ultimate salvation (moksha) even to such souls, ensuring their peaceful transition.