TamRandom Rune is a legendary Runeword created by combining a Tam Rune of Ritual and a Random Rune Rune of Invocation.
How to Create TamRandom Rune
You can create TamRandom Rune by adding the legendary Tam Rune of Ritual and the magic Random Rune Rune of Invocation to a two-socketed 
Helm, 
Chest Armor, 
Pants, or 
Two-Handed Weapon.
Overflow
TamRandom Rune can not overflow because the Random Rune Rune does not have an overflow effect.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.
Legions
Helltide