I know there are many factors that influences the transmission of HIV from an infected person to another. But....I want you to clarify this issue for me. Is it true that for HIV virus to be transmitted, it takes a viral load of 11000 and above to do so? Can an HIV+ person with a viral load less 11000(680 to be precise) transmit the virus to another or not?

No, it is not true that it takes a viral load of 11000 or any such number. First of all, the viral load that people get when they go to their doctor is a "snapshot" of the viral load of their blood at the time the sample was taken. It is not the viral load of their genital secretions. Also, the viral load of the blood (or genital secretions) can be different the next day or the day afer that. While it may be true that, in general, a lower viral load (less viral shedding) may reduce the likelihood of transmission of HIV, the bottom line is this: anyone living with HIV is capable of transmitting it to another person when there is an exchange of body fluids (genital secretions, blood) no matter what the measured viral load was the last time they were tested.