Correct spelling for the English word "Manifestible" is [mˈanɪfˌɛstəbə͡l], [mˈanɪfˌɛstəbəl], [m_ˈa_n_ɪ_f_ˌɛ_s_t_ə_b_əl] (IPA phonetic alphabet).
That may be manifested.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.