Mazal tov! Stitches are a barrier if they are removable. Absorbable stitches are not a barrier. The tape is a barrier, but can generally be removed after a week or so.
A cesarean birth is subject to the normal laws for a niddah, five days' wait and seven clean days. More likely it will be a number of weeks before you stop bleeding enough to use the mikveh. At that point, it is quite unlikely that it will be a problem to remove the tape if it has not fallen off.
If concerns about infection are still relevant by that time, they should be discussed with your physician. Both you and he/she should be aware that arrangements can be made for you to be the first to immerse in the mikveh pool after it has been drained and disinfected.