i used my father name-Krishna Rao(absence of surname) in rrb ntpc online registration, but in my 10th class certificate my father name-Dodla Krishna Rao (used surname Dodla)...is any problem during document verification?
There will not me a problem of of name defect during your counselling and registration process, as documents such as the Aadhar card, or birth certificate will clearly signify your father's name.
There are less chances that the officials will question upon your father details, and if they do you can provide them the documents with correct information.
Have a good day. All the best!!