Its legal to sell instagram follower/likes in fiverr?
No it’s not allowed.
It’s not legal to sell followers/likes/views/subscribers on any social media, or to promise/state/imply that your buyers will get them.
If you try to do it anyway, sooner or later, your gigs will get removed, and if you keep trying, your account could get banned, too.
It is not allow And you could get ban for it