Hi there, my 9 month old is well off the charts in size (99th percentile) and super tall. He moves around a lot in his sleep, always gets his legs stuck in the bars of the cot and gets stuck sideways because of his height. I’m not sure on what to do going forward to give him the space he needs while also giving him a safe sleep environment. We want to move to a floor bed with rails in the future but it feels too soon. Some advice would be helpful, thank you!

Does he wake when he gets his legs stuck?
Does he wear a sleeping bag when in his cot?

If you decide to move him to a floor bed, there are a number of things to consider in relation to safety.
eg what does he now have access to that he is no longer in a cot.
We have a number of resources about that.
https://rednose.org.au/article/where-to-sleep-a-child-who-has-moved-from-a-cot
https://rednose.org.au/article/making-your-home-safe-before-moving-a-child-from-a-cot-to-a-bed

Also have a look at the Cot to Bed brochure which provides information, particularly in relation to risks, where to place mattress, use of sleeping bag on floor bed & safety of railings.
https://rednose.org.au/downloads/RN3356_Cot_Bed_DL_Oct2018_Online.pdf