Have you tried looking for a definition?
Student or Learner
where we can use "unti now"?
Welcome to the forum, atharkamal.
We like members to try to form sentences of their own before we do. Your sentence(s) will give us an idea of what sort of help you need.
And I assume that your title was meant to be "Learner". Check the spelling of your words before you post.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.