Correct. If you check the visa bulletin, Under the f-4 category, the current priority date is 11-1-94, which means that if your uncle submitted the petition in 97, you got approximately 2-3 more years. Once your mom's date becomes current, she can then begin to process to become a permanent resident. You would not qualify since you'd be over 21. However, it is possible to get a really good lawyer like Carl Shusterman and take this to court as your last res

"Apart from that Ins is now making it impossible for employers to sponsor their workers. It use to be that any unskilled worker could get through but now you gotta be a professional and even then they still give you hell."

It's not so much that they give you hell, but even if it were just for unskilled workers, the process is long and tedious. First, they have to make sure that you would not be displacing an American worker, so you have to obtain an approved labor certification petition. You also should have a committed employer who'd be willing to go to through the process, which is long... would take about a year. It's just standard procedures.

Are you in college?