Will the plants be too tall for the tent?

600w Dual Spectrum
24/0 Cycle
10 gallon Smartpots
In veg for a month and now are 9'' tall
Top height of the light in a tent is 6'
I intend to top them two times and veg them for month and a half more,thats 2 and a half months all together before putting them in 12/12 cycle
Will they grow too big for me?

Why would you use 10 gallon pots when you have height concerns? Also, a 0/24 light cycle means 24 hours of dark. I think you meant 24/0.
Here is how you should have been thinking when you started the grow --


Hmmm, looks like the tent height is going to be my limiting factor, (limiting factor = that one thing restricting you from unlimited size). With
a 6 foot ceiling I have to figure the light will hang down a foot. That leaves 5 feet to play with. But a 600W bulb is hot enough so you have to
keep plants 24 inches away. Plus, most pots are at least a foot deep. By the time all these elements are factored in you are going to want plants
that finish around 36-40 inches tall. Plant height is measured from the top of the pot to the top of the plant. 10 gallon pots are rarely required as
they are usually way to large for indoor grows. 5 gallon pots are generally too big for your space. I grow a lot of indicas that finish at 36-40 inches.
I use a range of pots from 6 quart, 1 1/2 gallon, to 3 gallon size. I suggest you get some 1 1/2 to 2 gallon pots and find some short bushy indicas
to grow. Also, I top or FIM most plants halfway thru veg. Keeps them short and bushy.

BigSteve.

Reply your pot size only makes a difference for how large you intent your MASS of your plant tot get. Many people have only one plant under a 1000w light and just keep tiping them to keep their plants super squat and fat! I recommend FIMING... Google fiming its much better than toping and you dont loose your inital top!

If your gonna veg that long drop the light cycle back to 18/6. Your gonna top, so that's cool. Start tying down the branches after you top, start filling in the width of your tent with lateral branches.
or-
buy sum bush master, when she gets to the height you want "bush master" the plant. She'll stop elongating, and start growing laterally. Also stops elongation in flower.

I am tying them down from day 10,do you think me putting cycle on 18/6 is gonna give me more realistic view on final size because they will elongate more,or some other reason?

You have a long veg time, your worried about height issue, 24/0 will give you a plant with node lengths farther apart. If it was my grow I'd run 18/6 considering the factors involved. Like that one dude said "FIM" or pinching off the meristem will cause the plant to bush out. Draw back to that alot of buds of similar size. Topping off a couple times like the other dude said will give you several tops both filling in the top of the plants canopy. Another thing is the canopy, is or should be thick with branches blocking the light to everything below the canopy. Consider side light or trimming the growth below your canopy. That's if it fills-in dense, how I'm picturing it a couple weeks before flower.

I will top them 2 times as said and lolipop 1 week prior to 12/12 I think in my opinion with SCROG feature they will be right in size,and by your advice I am considering changing to 18/6 in two weeks,thanks