[en] Suppression of high energy hadrons compared to pp collisions, called 'jet quenching', is one of the important feature of the strongly interacting matter, Quark Gluon Plasma (QGP), produced in high energy heavy ion collisions. This phenomena occurs due to the energy loss of high energy partons, i.e. light and heavy quarks which are produced from initial hard collisions. Heavy flavour hadrons, containing charm or bottom flavour, are important probes of deconfined matter produced in ultra-relativistic nuclear collisions. Heavy quarks are produced only in the early stage of collision, and loose energy while traveling through QGP medium, which is reflected in the p_T distribution of corresponding hadrons (D or B mesons). The dynamic evolution of plasma will thus affect the fractional energy loss as well as nuclear modification factor R_AA of heavy mesons which will be studied here. Report here is the fractional energy loss of charm and bottom quarks with path length L fm while traversing through the thermally evolving plasma for energy E = 10 GeV