*in a vaccuum
Einstein's Special Theory of relativity postulates that the speed of light in a vacuum is same for all inertial frames.
suppose a neutrino is there moving at the speed of light
For a neutrino to move at $c$, it has to be a massless particle.
We're not sure of that yet. Apparently the existence of neutrino oscillations prove that neutrinos have some rest mass (h/t Neuneck).
But yes, if any particle moves at $c$ in one inertial frame, it does so in all inertial frames. An example of this would be the gluon.
However, if the neutrino has mass, it will never be able to reach $c$ in any inertial frame. Particles going at subliminal speeds cannot be sped up to $c$, and particles moving at $c$ cannot be slowed down.