This depends greatly on your individual circumstance.  Some asymmetries can be repaired, and some can’t.  And most people have some facial asymmetry anyway to a degree. A surgeon who is skilled can assess any asymmetries you may have and help you come up with a surgical plan to minimize them as best as possible.  A skilled surgeon will also be able to highlight those asymmetries that can’t be improved upon, and let you know up front so that you don’t go in with unrealistic expectations.
I recommend visiting with a Board Certified Plastic Surgeon who can do an assessment and discuss with you what options would best achieve your goals.  It is possible that a Botox treatment could assist in lifting the brow in question, or a unilateral brow lift may be a good option, if you are a candidate for the procedure.  But the only way to assess this properly is a one-on-one consult, so your surgeon can examine you and discuss the options.  Just keep in mind that while asymmetries can be reduced, we all have them to a degree and most often they can’t be completely corrected.