Is it permissible for a woman engaged to be married to marry a man who bought a nationality and attributed himself to its seller who is not his father? And is the marriage considered valid in Islamic law?

There is no impediment to your marriage to a man who attributed himself to someone other than his father in official documents. The marriage is valid. However, this attribution may lead to legal harms such as inheritance and issues of unlawful closeness (mahramiyyah). Therefore, it is necessary to correct the lineage in the official documents if possible, or to take the necessary precautions to avoid these harms.