What is the ruling on changing a family name (surname) to "Osmanoğlu" with the intention of being attributed to the ancestor Uthman, and is this considered an attribution to other than one's father?

There is no legal impediment to being attributed to a distant grandfather, or to using the word "oğlu" instead of "ibn" (son). This is evidenced by the Prophet, peace and blessings be upon him, saying on the Day of Hunayn: "I am the Prophet, it is no lie; I am the son of Abdul Muttalib." Scholars have mentioned that attribution to the grandfather is equivalent to attribution to the father for the purpose of identifying a person.