You haven't mentioned your Father's actual name. Nevertheless, you need to contact an advocate and get an Affidavit done stating that all the names Moti Lal, Motilal and Motilal Dangi belong to the same person. The advocate will know the process of getting an affidavit done for that purpose. So you can use that affidavit and then there shall be no issue whatsover. Getting this affidavit done is important because your father has "Dangi" in some documents and doesn't have it in other documents.And the details that you enter in your 10th pretty much remain the same throughout and so it is important to get that right.