  We study an impact of self-interacting bosonic dark matter (DM) on various
observable properties of neutron stars (NSs). The analysis is performed for
asymmetric DM with masses from few MeV to GeV, the self-coupling constant of
order $\mathcal{O}(1)$ and various DM fractions. Allowing a mixture between DM
and baryonic matter, the formation of a dense DM core or an extended dark halo
have been explored. We find that both distribution regimes crucially depend on
the mass and fraction of DM for sub-GeV boson masses in the strong coupling
regime. From the combined analysis of the mass-radius relation and the tidal
deformability of compact stars including bosonic DM, we set a stringent
constraint on DM fraction. We conclude that observations of 2$M_{\odot}$ NSs
together with $\Lambda_{1.4}\leq580$ constraint, set by LIGO/Virgo
Collaboration, favour sub-GeV DM particles with low fractions below $\sim 5
\%$.
