  At Moriond 2019, Belle collaboration has announced new measurements on the
flavour ratios $R_D - R_{D^*}$ which are consistent with their Standard Model
predictions within $1.2\sigma$. After inclusion of these measurements, the
global tension in $R_D - R_{D^*}$ has reduced from $4.1\sigma$ to $3.1\sigma$
which is still significant. The measurements of these ratios indicate towards
the violation of lepton flavor universality in $b\rightarrow c\,l\,\bar{\nu}$
decay. Assuming new physics in $b\rightarrow c\,\tau\,\bar{\nu}$ transition, we
have done a global fit to all available data in this sector to identify the
allowed new physics solutions. We find that there are seven allowed new physics
solutions which can account for all measurements in $b\rightarrow
c\,\tau\,\bar{\nu}$ transition. We show that a simultaneous measurement of the
$\tau$ polarization fraction and forward-backward asymmetry in $B\rightarrow
D\,\tau\,\bar{\nu}$, the zero crossing point of forward backward asymmetry in
$B\rightarrow D^*\tau\bar{\nu}$ and the branching ratio of $B_c\rightarrow
\tau\,\bar{\nu}$ decay can distinguish these seven new physics solutions if
they can be measured with a required precision.
