Saw my uncleWatch
My family stopped talking to that side of the family 9 or 10 years ago but I saw my one of them. I saw my uncle in our area and I think he recognised me because he smiled at me. I just don’t know what to think of it. My parents just stopped talking to them because I think they just wanted to focus on bringing me and my siblings up as we were still in primary school then. They didn’t do anything wrong to make my family stop talking to them. I think they were quite helpful
You could bring it up with them, say that you saw your uncle the other day and that you were wondering about reaching out to them again now that you're older. With all due respect, cutting out family because your parents wanted to bring you up sounds like a complete non-reason for cutting people out. I would have thought they'd want you to be surrounded by nice family. You sound old enough to make these kinds of decisions for yourself. You might not have to tell them either, just reach out to your estranged family and simply don't tell your family. If you keep the communication to your phone/email/messages then they'll never know that you're talking to them again.
Do you have your own phone? You can use that to message/call your other family and your parents won't know, unless they for some reason check your phone. Telling them is probably the best thing to do, and hopefully they are positive. Good luck.