Mine is just over 7 months, sits unassisted, has started trying to crawl and pull himself toward standing and still doesn’t roll either I spoke to our paediatrician and she said rolling isn’t actually an official milestone and not to worry about it as long as he’s not showing any other signs of delayed development or other physical issues Every baby is different
Is he a chubby baby? It's literally a thing that chubby babies often roll a bit later. More body to move around
Our first rolled a couple of times and didn't roll again until he could crawl. It was almost as if he was like...oh now I understand why I needed that skill 🤣 He's currently 3 years old and very physically active and strong. So unless there are other things too that you feel aren't happening that should be, I wouldn't be too worried... But that's just from my one experience and an unprofessional opinion.