Had hernia repair 12m ago recently had surgery to remove scar tissue doc cut same incision when I move feels like something is ripping on the inside.

Not enough info. There are too many variables to answer. Location of hernia, type of repair, detail of re-exploration , etc. It could be related to scar tissue, and may be a normal sensation.
Visit required. Depending on the type of hernia and the specific of the repair, there are multiple reasons for your symptoms. Best to schedule appointment to see your surgeon to determine whether your symptoms are benign or whether further intervention is necessary. Good luck.