  Broad-line regions (BLR) are one of the main components that constitute the
phenomenological picture of active galaxies near the vicinity of the accreting
supermassive black holes. Both theoretical and observational studies have shown
that the BLR is made of dense, ionized gas clumps that have a strong virialized
distribution at parsec-scale distances from the nuclei. Using a theoretically
motivated photoionized gas model, I constrain the ionisation parameter (U) and
cloud density (n$_{\rm{H}}$) as a function of the strength of the FeII
emission. Recent observations in the reverberation mapping studies have
contested the standard radius-luminosity relation showing increased dispersion
in the relation, in particular, after the inclusion of highly accreting
quasars. I incorporate the departure coefficient that accounts for this
dispersion. This departure term in terms of the dimensionless accretion rate
($\dot{\mathcal{M}}$) and Eddington ratio
($L\mathrm{_{bol}}/L\mathrm{_{Edd}}$), also includes the virial factor that
accounts for the BLR geometry. I then combine the fundamental plane relation
for the BLR to connect the FeII strength (R$_{\rm{FeII}}$) in terms of U and
n$_{\rm{H}}$ using selected values for the shape of the broad H$\beta$ profile.
