I petitioned for my brother and his family in F4 category. I-130 was submitted on September 25, 2009 and was approved on 10/16/2009 after only couple of weeks. My nephew turns 21 in 2021 and PD will not be current for another 3 years. does this mean my nephew will not immigrate with his family after he turns 21? is there any other remedy that applies for such situations? thanks
By the description of your case, CSPA does not really apply to you. Therefore, yes, your nephew will be aged out by the time that the visa becomes available.
An option to overcome this problem is to have his family immigrate to the US first and then petition for him as a F2B which should take only a couple of years.
An other option is if he's a student, he might be eligible to come as a F-1 student visa first and then while studying here have his family file for the F2B once they receive their green card. Please note that this option requires careful planning.