  We study the possibility of generating deviations from tri-bimaximal (TBM)
neutrino mixing to explain the non-zero reactor mixing angle within the
framework of both type I and type II seesaw mechanisms. The type I seesaw term
gives rise to the $\mu-\tau$ symmetric TBM pattern of neutrino mass matrix as
predicted by generic flavor symmetry models like $A_4$ whereas the type II
seesaw term gives rise to the required deviations from TBM pattern to explain
the non-zero $\theta_{13}$. Considering extremal values of Majorana CP phases
such that the neutrino mass eigenvalues have the structure $(m_1, -m_2, m_3)$
and $(m_1, m_2, m_3)$, we numerically fit the type I seesaw term by taking
oscillation as well as cosmology data and then compute the predictions for
neutrino parameters after the type II seesaw term is introduced. We consider a
minimal structure of the type II seesaw term and check whether the predictions
for neutrino parameters lie in the $3\sigma$ range. We also outline two
possible flavor symmetry models to justify the minimal structure of the type II
seesaw term considered in the analysis.
