Hi and welcome to Knitting Help!
This can be done but the question is whether it's easier to reknit from the beginning of the mistake or try to cut out the extra rows and graft the two sections together. The grafting will be easier if you can do it in an area of plain knitting without floats, even if it's only 2-3 rows. You can do something similar to "length re-assignment surgery"
and graft the two pieces together with Kitchener
Worth a try. Even if it doesn't work you can reknit (I know that is a painful suggestion) from either the top down or bottom up.
Can you tell us the name of the pattern?