The enzyme which facilitates internal rearrangement in 3-phosphogylceric acid to form 2-phosphoglyceric acid is
Phosphoglycero mutase
Phosphoglyceromutase is an enzyme involved in glycolysis that catalyzes the internal transfer of a phosphate group from C-3 to C-2. In other words, the phosphoglyceromutase brings about the conversion of 3-phosphoglycerate to 2-phosphoglycerate.