What are the drop rates for items in pots?

According to speedruns.com, this is the drop table for everything in the game. Enemies and pots included.

I'm the creator of the drop table you linked. Pots in Ocarina of Time are 100% hardcoded, they should always drop the same item.

What you'll find is some pots use a room flag and others use a dungeon flag to mark whether their item has been grabbed or not, dungeon flag pots will not give you the same item again until you exit and re-enter the dungeon.

Majora's Mask is different, and actually does occasionally use drop tables for some pots, which tables they use though vary from pot to pot.

If you're interested, OoTMap.com, my Ocarina of Time Interactive Map, features a Containers tab where you can see what every pot and box in the game is set to drop.