  The recently measured experimental data of $^{79,81,83}$Se isotopes have been
interpreted in terms of shell model calculations. The calculations have been
performed in ${f_{5/2}pg_{9/2}}$ space with the recently derived interactions,
namely with JUN45 and jj44b. To study the importance of the proton excitations
across the $Z=28$ shell in this region. We have also performed calculation in
${fpg_{9/2}}$ valence space using an ${fpg}$ effective interaction with
$^{48}$Ca core and imposing a truncation. Excitation energies, $B(2)$ values,
quadrupole moments and magnetic moments are compared with experimental data
when available. Present study reveals the importance of proton excitations
across the $Z=28$ shell for predicting quadrupole and magnetic moments.
