I am looking for a water filled lawn roller. Does anyone know where I can buy one from?

Something like this.

I've never seen one for sale in Thailand.

I assume you want to use it for smoothing the surface and joining the seams for sod lawn installation. You may have to resort to using a plastic drum and just pushing it around. Or make a stamp out of wood, a big 2" x 12" plank; lay the sod first on well prepared moist soil, get the soil and sod muddy wet (experiment with just the right amount of muddy, not too much or too little) and then lay the stamp down and walk/jump on it to mesh the muddy soil/sod surface together. Fill the seams first as best possible with loose soil or sand.