dear aspirant,

While you fill up your improvement form, you add a photo copy of your original marksheet wherein you also have your practical marks.So the same marks are printed on your new mark sheet and you don't have the option of giving practicals again. Thus there is no rexam for practicals the previous exam marks  are carried on to the   new improvement marksheet.

regards.

HEY!

While you fill up the form for improvement exam, you also attach a copy of your original marksheet, wherin you also have your practical marks there.

So, the same marks are printed on your new marksheet. You will appear for the theory papers and can improve in them, practical marks will be carried forward from the previous marksheet.

I hope this helps you!