  X-ray spectroscopy of galactic black hole binaries serve as a powerful tool
to gain an overall understanding of the system. Not only can the properties of
the accretion disk be studied in detail, the fundamental properties of the
black hole can also be inferred. The pursuit of these objectives also leads to
an indirect validation of general relativity in strong field limit. In this
work we carry out a comprehensive spectral analysis of the galactic X-ray
binary MAXI J1631-479 using data from NICER and NuSTAR observatories. We trace
the evolution of the accretion disk properties such as density, ionization, Fe
abundance, etc as the source transitions from a disk dominated soft state to a
power law dominated hard intermediate state. We provide strong constrains on
the spin of the black hole and the inclination of the inner disk. We also use
the soft state NICER observations to constrain the black hole mass using
distance estimates from optical observations.
