  Recent research has indicated that the Standard Model (SM), while
historically highly effective, is found to be insufficient due to its
prediction of zero mass for neutrinos. With the exception of a few, the
majority of the parameters related to neutrinos have been determined by
neutrino oscillation experiments with excellent precision. Experiments on
neutrino oscillation and neutrino mixing have shown that neutrinos are massive.
To fill in gaps, discrete symmetries are becoming more common alongside
continuous symmetries while describing the observed pattern of neutrino mixing.
Here, we present a $T_7$ flavor symmetry to explain the masses of charged
leptons and neutrinos. The light neutrino mass matrix is derived using seesaw
mechanism of type I, which involves the Dirac neutrino mass matrix as well as
the right-handed neutrino mass matrix. We estimate the
Pontecorvo-Maki-Nakagawa-Sakata matrix ($U_{PMNS}$), three mixing angles,
$\theta_{12}$, $\theta_{23}$ and $\theta_{13}$, which are strongly correlated
with the recent experimental results. The extent of $CP$ violation in neutrino
oscillations is obtained by calculating Jarskog invariant $(J_{CP})$ on the
behalf of $U_{PMNS}$. We also find the masses of three neutrinos and Effective
Majorana neutrino mass parameter $\langle m_{ee} \rangle$ which is $1.0960$
$meV$ and $10.9217$ $meV$ for normal and inverted hierarchy, respectively.
