Reusing materials is always a good thing. Tiles by themselves would not have the structure needed to hold any amount of soil, surcharge.
You need to build a structure that can handle the stresses of soil and water and then use the tile OVER this structure. The tile will enhance the structure's strength...sheer strengths.
Tile is not structural by itself.
The other issue is the leaching of lime. Makes the soil great for plants
that love an alkaline soil. Not so much for the plants that need a more acidic soil.
I would double dig the bed that the raised structure is installed upon. Then get a piece of plywood and stomp it down (I know sounds conflicting but not). Install your planter and use potting soil, not garden soil.
That would be me. A raised structural planter without a bottom IS ABLE to use garden soil, iffy, but doable. Sterilized potting soil without fertilizer or water holding gimmicks would be ideal in your planter (also a bit acidic to offset the mortar/lime).
Dump bagged sterilized potting soil into your planter firming the soil as you fill every 6"? Water well. Watch how it drains, how long it takes to drain.
Using potting soil you don't have to worry about drainage and infection by fungal spores. Dig little trenches along the periphery of your raised bed; 6"X8"? There abouts? That will enhance drainage in a big way and remove water to where you want that water to go.
If you have a bottom to your planter you HAVE to use potting soil, never garden soil. And the bottom should have at least 1/4" of space/air between the patio, garden soil proper. Pots and planters have to have this air space between the pot/planter and the surface it sits upon.
Never ever put gravel or logs or packing peanuts or rocks beneath the soil and above the drainage hole. ONLY potting soil goes into that pot/planter.
What plants do you imagine growing in these planters/pots? What is the environment? Beneath an awning or full sun? Exposed to wind? Where is it that you live on this planet, what zone?