Should I drink geritol before my surgery which will be in 4 weeks? TT & BBL.

You should discuss preop instructions with your surgeon. I do not commonly recommend a product like geritol to patients.

The question is why you want to take Geritol.  If the goal is to guard against anemia, the blood loss is not significant when the operation is performed carefully and this is not something which would require prophylaxis.  If you are already anemic, then this is something to discuss with your surgeon, both in terms of medical clearance and in ascertaining your hematocrit levels.  

The only reason to take Geritol before the surgery is if you are anemic. If you are anemic, your doctor needs to make sure the anemia is treated before doing any major surgery on you. If you are anemic due to low iron levels,  there are better ways to replace your iron than Geritol.