My box is 6 feet tall... and I'm honestly on my first legit harvest (I have a grow journal going on here), but a bagseed plant and a white widow plant are about 2-4 weeks from being done and they are about 3 feet tall. It depends how you hang your light. I keep mine hung at about 4 feet since I'm doing a sea of green concept, with different-aged plants flowering.
I don't expect my plants to grow much more in height, so to answer your question my indicas are staying around 3 feet. I have chemdawg and sour D going and those are 2 weeks into flowering and almost bigger than my plants 8 weeks into flowering! Depends what you grow.