Hello Maheah. Given below is the link provided for all the information regarding improvement exam that is the ljnk, form, dates, results and other stuff. 

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.entrancezone.com/admissions/cbse-improvement-exam/&ved=2ahUKEwjwtcrJ7M_iAhWc7HMBHcXbCKsQFjAEegQIDxAI&usg=AOvVaw150ta1hZoR4XJfnFV6o0xA