If you got passed in the practical exam then the marks from there will be carried forward and you need not give the practical again, however, if you failed you will have to give the practical exam again, since its an improvement exam you will have to opt for giving just the written or practical exam, if you could not pass the practical exam then there is no other option but you will have to appear for both.

after giving the exams final marksheet will be updated, for now you need to keep in mind that improvement exam will be taken keeping in mind both aspects of written and practical examination.