Question on my constraints growin in my 5x5x6 tent.. 5 plants for 3 months vegging?

I want to grow 5 autos and at the same time while the light is running 18/6 I want to veg 5 fem plants at the same time, and switch the lights to 12/12 when the autos are done, and flower for 8~ weeks.

My question to all of you with more experience than I have (not much,) is this reasonable? like i said, tents 6.5 feet, but i would say loses a good 1.5" feet to light/fan. so 5 feet tall is possible. there is a 600 watt hps with cooltube and 400w without.

BUT

Could I somehow control the growth/height to ensure that they do no reach the roof?
Please give me some advice on this, as I plan to start very soon!

You could top the plants to keep them short and you will get 2 top buds, just make sure you don't do this within a month before flowering because pruning defuses floral hormones or bend them while vegging. What kind of plants are they, what is their expected height ? Maybe you don't need to do anything at all.Anyways hope that helps.

A variety of strains, all free on attitude.. but thanks forthe adice I was wondering about that

no more input?

so far i now have the idea to top them but thats it... any other advice?

Should this be in another section

It really depends on the strain and sometimes that's not full proof as you may get a sativa strong pheno. I currently have a 4.5 feet Aurora Indica, it was to remain short and stocky .. well didn't happen (3 months vegged by the way). What size pots are you using? For that space (3-4) 5gallon pots would be nice or (5) 3gallon pots.
Happy growing

Oh yes pot size not foolproof but about 1 gallon of pot size per foot of growth I believe.