Study help

Take atleast 6 months leave before Exam, upto that you have study atleast 2-3 hours a day with your Articleship, or atleast have to cover dailu whatever done in Classes.
In overall, your Studies must started 1 year before Exam.
Daily and Regular Studies will make it happen properly.
This is my Thinking only for suggestion.

But abhi offc mai abhi itna kaam nhi hai most of the time sir offc mai nhi hote sometimes pura time ese hi nikal jata hai...

Then take your notes along with you and go through them
You can also make use of youtube for listening to videos

It's all about managing your studies with job. but as usual its difficult sometimes. I think you should openly speak to your principal and

I would suggest don't take leave as of now because ultimately your principal would add on these leaves while signing your form. You can start reading a subject you like, in office. You said there is not much work there ,so make better use of it.