Would you be able to stop a nuclear missile by hitting it with a liquid nitrogen missile, As a means to prevent the nuclear radiation from spreading or falling to the ground from impact?
Short answer: NO
Long answer: a liquid nitrogen missile is nothing more than a mass of liquid contained in a missile, impacting the incoming nuclear missile. While kinetic weapons can be used to destroy the target, it is preferable to use dense materials, in order to deliver larger amount of kinetic energy. Using liquid nitrogen for this is like using a sponge baseball bat to hit someone intruding your house.
If the goal of using liquid nitrogen is to use the cooling consequent to the evaporation of the nitrogen as a mean to embrittle the nuclear missile, it's a vane hope: evaporation of nitrogen and cooling of the mass of the missile takes time, while the impact will last, at most, few tenths of seconds.
The only effect you would achieve would be a nice puff of condensing humidity once the liquid nitrogen gets sprinkled around by the impact and start evaporating, cooling the atmosphere around it.