elements is the high Z number which poses high coulombic barrier for the charged particles to initiate nuclear reactions at stellar core temperatures. This impediment to further nucleosynthesis is rescinded with the help of neuron capture processes in the stellar core to form heavier isotopes beyond iron group nuclei. These processes are further classified into slow (s-) and rapid (p-) neutron capture processes depending on the neutron capture time scale $\tau_n$ and beta decay time scale $\tau_\beta$ for nucleus to endure beta decay. As discussed earlier that weak interaction and gravity are the mentor that drives the stellar evolutionary process and its subsequent death in a cataclysmic explosion. The main weak interaction processes that play an effective role in the stellar evolution are beta decays, electron and positron capture processes and neutrinos emission/capture processes subject to the physical conditions available for these processes in the stellar core. These weak decay processes are smitten by Fermi and Gamow-Teller (GT) transitions. Fermi transitions are straightforward and are important only for beta decays. For nuclei with $N > Z$, Fermi transitions are Pauli blocked and the GT transitions dominate and their calculation is model dependent. Spin-isospin-flip excitations in nuclei at vanishing momentum transfer 