Why do you think Pakistani LACM and SLCM have different ranges?
Probably, the changes needed to make the missile sea-launchable affected the range by either decreasing the size (fuel capacity) or increasing the weight of the missile, or both. Launching an air-breathing missile by first shooting it through the water is significantly different than launching it straight into the atmosphere from the land-mobile launcher, so it isn't surprising that other changes had to be made to the missile itself -- changes that reduce its range.