Do you know what kind of corys they are?
There are basic cory breeding techniques but some species need a few different things.
The basics of protein to condition them then a large
water change with water a few degrees cooler.
It's recommended they be in a tank alone as the other tank mates may not appreciate the cooler water. This will also allow you to remove the parents after they lay or after the eggs hatch.
I suggest a lot of research before attempting to breed them though so you will be prepared.
Carol