  We present spectral and timing properties of the newly discovered X-ray
transient source, MAXI J1535-571, which is believed to be a Galactic X-ray
binary containing a black hole candidate (BHC) as the primary object. After its
discovery on 2017 Sep. 2, it has been monitored regularly in multi-wavelength
bands by several satellites. We use archival data of Swift (XRT and BAT) and
MAXI (GSC) satellite instruments to study accretion flow dynamics of the source
during the outburst. During its outburst, the source became very bright in the
sky with a maximum observed flux of $5$~Crab in the $2-10$~keV GSC band.
Similar to other transient BHCs, it also shows signatures of low frequency
quasi-periodic oscillations (QPOs) during the outburst. Spectral data of
different instruments are fitted with the transonic flow solution based
two-component advective flow (TCAF) model fits file to find the direct
accretion flow parameters. Evolution of spectral states and their transitions
are understood from the model fitted physical flow parameters and nature of
QPOs. We also estimate probable mass of the black hole from our spectral
analysis as $7.9-9.9~M_\odot$ or $8.9\pm1.0~M_\odot$.
