Regarding f4 visa in USA and whether my son is age out or not

Based on the details you provided—your 2007 petition, the September 2019 visa availability, and your sons’ dates of birth—a preliminary assessment is possible. Your younger son (DOB: 10/29/2001) was well under 21 when the visa became available, so he is very likely protected. For your elder son (DOB: 08/29/1997), a precise CSPA calculation depends critically on the exact date your I-130 petition was approved, which determines the \"time pending\" deduction. This is a time-sensitive matter.
To give you a definitive answer, we need to examine the official petition approval notice and your documentation. We recommend a formal review of your papers before the interview to assess eligibility and ensure proper preparation.
Please let us know if you would like to proceed with a consultation.