Based on the effective neutrino potential up to order MW-4, we study the emission, propagation, and oscillation of multi MeV-GeV neutrinos within a medium with strong magnetic field amplified during a binary neutron star merger (1015 G) and in black hole-neutron star merger scenario (1012 G). We also calculate the number of neutrino events expected on several ground-based neutrino telescopes for the GW170817/GRB170817A event, this allows us to estimate the necessary conditions a GRB must have to produce neutrinos that can be detected on Earth. This kind of neutrinos could provide valuable information about its progenitor and the topology of the magnetic fields involved in mergers. Comparing with a well-known set of experimental parameters, we also found that the characteristic resonance length of these neutrinos corresponds to a typical length scale in which these MeV-GeV neutrinos within the fireball are produced. Finally, we calculate the neutrino opacity in a GRB event, finding that neutrinos do not escape isotropically but they are collimated in a preferential direction along the jet propagation way. This gives us a powerful tool to determine which is the mechanism by a GRB is originated.