I had inner thigh lift 6 days ago and I'm feeling a burning pain. Is this normal?

First of all, congratulations on your thigh lift, eloisamagallon!
It’s only been six days since your thigh lift, so it’s normal for you to feel some sort of pain, soreness, and discomfort. Each person has his or her own pain threshold, which is probably why you feel a burning pain in your incision site.
Please take the prescribed pain meds that your plastic surgeon gave you to help you relieve pain. But if it becomes unbearable, don’t hesitate to follow up with your reputable and board-certified plastic surgeon.
Good luck!

Good question. After body contouring surgery I inform patients that almost any degree or type of discomfort is normal for the first two weeks; after this time the intensity and frequency should decrease noticeably over the next 6 weeks, and should be uncommon after 2 months post-op. With certain methods of medial thigh lift (such as a transverse technique with horizontal scars) the discomfort may be prolonged, and sometimes more severe. Asymmetric discomfort is also common, with one side "misbehaving" more than the other. Follow the activity restrictions and postoperative compression instructions to keep discomfort to a minimum, and contact your surgeon with any concerns.