I am in a weird spot right now, since my chronic back pain i had to stop weight lifting because it causes scar tissue and pain. I am now doing rehab using resistance bands, i need to know if this will deplete glycogen in my muscles and help me get into ketosis.

I was also looking at swimming and sauna, hot baths and vapor baths to help with the weight loss

You can get a very intense workout using bands and will deplete glycogen as long as you are using a lot of resistance.

Diet is what will put you into ketosis.

Forget saunas etc for weight loss. It's not permanent. You will only lose water and you will put that back on when you eat or drink anything containing water.

Exercise is not an efficient method to lose weight. It is not efficient to eat too much one day and try to burn it off the next day. If you want to lose weight then simply eating less is the way to do it.