If you are worried about 4-6 feet, the answer is NO. You are are restricting it too much. Because it sounds like you would like to hear 3 feet is ok and 2 1/2 feet in diameter.
See this thread we just discussed exactly this topic.

Try a different variety, Red Robin, for instance.

PC

You can control the height by toping it nd letting as many side branches to grow as you want. This has to be done early on when the plant is , say, unde 2 feet tall. Then you top it such the 2 -3 leaf nodes remains. Now from each leaf node one branch will grow, almost all at the same time.

I have 2 KB plants. The main on one of them broke in handling during the plant out. Then 4 branches emerged. Now they are each about 2 ft tall. The other one is close to 4 ft tall.
The point is that you can grow an indet short and bushy, if you want to.

Sey

"The point is that you can grow an indet short and bushy, if you want to."
Yes, it will live. However it will not be worth the trouble/unproductive. That's why determinate and dwarf tomatoes are so popular for these applications. Otherwise everyone would just prune LOL.
PC

Like PC said, it all depends on if you want the plant to live and actually produce more than a couple of tomatoes. Even though this variety is a relatively small indeterminate one, what you are wanting to do just doesn't fit the nature of this particular variety.

Since plant size is your primary concern then you need to try one of the hundreds of other small, bred for container, varieties as they will better fit your limitations.

Dave

Why do you think that the side branches won't fruit ?
You always advocate that one should not prune the side branches because they will produce. Here we try to grow just that , side branches, selectively , This is a French pruning technique.

YMMV

French Pruning

Bonzai !!!!