Hello dear,

Hope you are doing well!

You havent mentioned the board through which you have done your 12th.

But As per the latest update of CBSE Board, students can give the improvement exam in the same year. You just have to fill the form from boards official website.

if you ask me about the state board, then every state has different rules and guidelines. You can go trough your state's board guidelines on their official website and can find out whether you can give improvement in the same year or not.