hi.. it might sound fine on paper.. but when you have 6 adult aro sharing that space it would def look crowded.. i'd go with 4 max..
10Feet Length X 10Feet Width X 3 Feet Height. Is it overstock or not?
Based on my 4 aro in a 8x3' space.

It's a matter of personal opinion. Here are mine:
Not overstocked. Each aro gets ~330 gallons each. Thumbs up.
Overstocked. Each aro only gets ~110 gallons each. Thumbs down.
If you ask the guy that was trying to keep 5 aros in a 180 gallon, he would probably tell you to get a few dozen more.
PS- All of his aros "mysteriously" died.
Each aro has full access to all areas of the tank.