Is it permissible for me to take from the inheritance that devolved to me after the death of the father who raised me, especially since I am registered in the civil status registry and everyone around me insists that I take it, given that I am poor and in need?

Adoption is forbidden in Islam, and it is obligatory to change the name and lineage in official documents to the real father. The adopted child has no right to inheritance. The deceased's sister's daughter is a relative by blood (dhawi al-arham) and inherits half by kinship, and the remainder by رد (reversion), thus she is entitled to the entire estate.