It seems that Lee could only open the 6th gate even with the training that Guy did with his dad. So why can't Lee open the 8th gate yet? He said when Guy opened the 8th gate, "AMazing, I can only open to the 6th gate."
Do you wanna know the require to open 8 gates? or Lee can open 8 gates? etc..Questions...Right?
How many gates can rock Lee open?
Through Guy's teachings, Lee learned to open the first five of the Eight Gates at age 12, the sixth age 17, and the seventh at age 20. He is recognised as a genius for this feat by Kakashi Hatake, who notes it is highly difficult for even the most talented ninja to open even one gate.
So the conclusion he can also able to open 8 gates.But the reason to avoid the 8th gate probably known as "The Gate of Death".You will get end of fight.
The require to open is basically it's based on opponents will power.No one would like to open the death gate.
This link would be useful to know more about gates.