Hii

If you have mentioned APPEARING as your  status of qualifying examination, then you will have to enter the details of class 10th. 
The board as well as roll no has to be of class 10th and not 12th.
After the result if you get selected, that time you will have to provide the class 10th as well as 12th certificates and then only will you admission process be completed.

Hope this helps
Incase of doubt feel free to revert back
Thanks!!