The melting point of paraffin wax (which contracts on solidification) __________ with pressure rise.

The melting and boiling points of all the substances increase with increase in pressure which can be explained by Le Chatelier's principle or molecular behavior.
Molecular behavior: when the pressure increases the intermolecular or attractive forces between the molecules increases so, more thermal energy is required for conversion of solid to liquid. Hence, melting point increases.
There are some exceptions for this behavior also eg: water.
So, for paraffin wax with increase in pressure the melting point increases.