  We present results from ${\it NuSTAR}$ and ${\it SWIFT}$/XRT joint spectral
analysis of V4641 Sgr during a disk dominated or soft state as well as a
powerlaw dominated or hard state. The soft state spectrum is well modeled by a
relativistically blurred disk emission, a powerlaw, a broad Iron line, two
narrow emission lines and two edges. The Markov Chain Monte Carlo simulation
technique and the relativistic effects seen in the disk and broad Iron line
allow us to self-consistently constrain the inner disk radius, disk inclination
angle and distance to the source at 2.43$^{+0.39}_{-0.17}$ R$_g$ (GM/c$^2$),
69.5$^{+12.8}_{-4.2}$ degrees and 10.8$^{+1.6}_{-2.5}$ kpc respectively. For
the hard state, the spectrum is a power-law with a weakly broad Iron line and
an edge. The distance estimate gives a measure of the Eddington fraction,
$L_{2.0 - 80.0 keV}/L_{Edd}$, to be $\sim$1.3 $\times$ 10$^{-2}$ and $\sim$1.9
$\times$ 10$^{-3}$ for the soft and hard states respectively. Unlike many other
typical black hole systems which are always in a hard state at such low
Eddington fraction, V4641 Sgr shows a soft, disk dominated state. The soft
state spectrum shows narrow emission lines at $\sim 6.95$ and $\sim 8.31$ keV
which can be identified as being due to emission from highly ionized Iron and
Nickel in an X$-$ray irradiated wind respectively. If not due to instrumental
effect or calibration error, this would be the first detection of a Ni
fluorescent line in a black hole X$-$ray binary.
