Hello Aspirant!
As you have secured only 76% this time hence you have to again give the cbse improvement exam in 2020 only in that 1 subject in which you want improvement hence you will be eligible to give only the theory exam in that improvement part.
Hope this helps you :)

Hello Aspirant!
As you have secured only 76% in your board exam hence when you will again give the exam you will only have to give the theory exam ( only if you have passed your practical exam) in the next compartment time.
Hope this helps you :)