Hello Kishan Patel

Yes you can. You can appear for the same through NIOS board. But what i will suggest is if you already have a PCB class 12th certificate,  just add up a subject to it. It would be really beneficial for future purposes too and even if you score less on the other exam you can get away with it as it was a Extra subject that you opted for later. Or else just take a drop and retry for PCB again. It will save up a lot of your time and effort.

Hope it helps you.