WTS claims that Adam would have been created 4026 BCE (so it would be 6037 years now), and:
*** it-1 p. 15 Abel ***
Since Seth was evidently born shortly after Abel’s death and when Adam was 130 years of age, it is possible that Abel may have been as much as 100 years old at the time of his martyrdom.
So "it is possible" that Abel was born around 3996 BCE or 6007 years ago. But actually the Bible does not mention his age at all. He may as well have been 30 years old instead of 100. If he ever lived, of course, which I don't believe.