  In this manuscript, we analyze the structural properties of $Z=119$
superheavy nuclei in the mass range of 284 $\le$ A $\le$ 375 within the
framework of axially deformed relativistic mean field theory (RMF) and
calculate the binding energy, radii, quadrupole deformation parameter,
separation energies and density profile. To investigate the phenomenon of shape
coexistence the RMF calculations are performed within three possible solutions
i.e. prolate, oblate and spherical configurations. To get a better
visualization of nucleon and total matter distribution, two-dimensional contour
representation of density distribution for $^{291}$119 and $^{303}$119 has been
made. Further, a competition between possible decay modes such as
$\alpha-$decay, $\beta-$decay and spontaneous fission (SF) of the isotopic
chain of $Z=119$ superheavy nuclei under study is systematically analyzed
within self-consistent relativistic mean field model.
  Our analysis confirmed that $\alpha-$decay is restricted within the mass
range 284 $\leq$ A $\leq$ 296 and thus being the dominant decay channel in this
mass range. There is no possibility of $\beta-$decay for the considered
isotopic chain. In addition, we forecasted the $\alpha-$decay chain of fission
survival nuclides i.e. $^{284-296}$119 and found as one $\alpha$ chain from
$^{284}$119 and $^{296}$119, two consistent $\alpha$ chains from $^{285}$119
and $^{295}$119, three consistent $\alpha$ chains from $^{286}$119 and
$^{294}$119, four consistent alpha chains from $^{287}$119, six consistent
alpha chains from $^{288-293}$119. Thus, such studies can be of great
significance to the experimentalists in very near future for synthesizing
$Z=119$ superheavy nuclei.
