Hi @mani_123, every Wednesday morning a new episode with 30 levels is released. You are at the top for a mobile device. On Windows 10 there are more levels available and that is now up to 4835.
It's up to 4835 but only on Windows 10. Mobile devices will always be behind because Apple and Android have to approve them first. The last level in mobile and on browsers is 4775.
Unfortunately there is no data collected world wide to see who is the highest for each level. The only way that you would find out anything about this is when you complete a level, playing through Facebook, and it tells you where you ranked among your Facebook friends.