In this work our purpose is to calculate the pion radiative decay constant using thernformulation of Bethe-Salpeter equation under covariant Instantaneous Ansatz(CIA)rnafter inclusion of both leading(LO) as well as next-to-leading(NLO) terms in the BSrnwave function of the pion. In this process we also calculate the pion Bethe-SalpeterrnNormalizer which is an extremely lengthy calculation