Greetings Sarang!
Hope you're doing great.
Sorry to hear that you couldn't perform well in the practical exam and hence looking forward to improving or you must have missed the practical and now want to give it a try again to increase your marks.
Unfortunately, it's impossible to appear for the pratical exam twice. Once your mark sheet has been prepared there is nothing you can do afterwards. Although, you can apply for the improvement in theory paper the same is not possible with the practical one. Again, if you just want to give a pratical exam from one school and want to sum up the score with theory from different school then it's also not possible. The same school should forward your practical marks where you're giving your theory paper.
So, either you can repeat you 12th from a different school, which I strongly discourage if you've already passed from the school. Now you should focus on getting into a good college and shift your focus there, No need to bother about your 12th percentage. It will be of very less use in future and that too for a CAT in case you'll plan to pursue an MBA in the near future.
Hope this will help. Do reach out in the comment section in case you need any help.
Cheers!
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