I filed I-130 for my dad and got an RFE to prove Father-Son relationship. Has anyone got this kind of RFE. Surprisingly my mom's I-130 was processed without any question. Please advise, if this is something I can do by myself  or if I need an attorney. I would aprreciate your help. 

The RFE demands evidence such as, Insurance forms listing the child as beneficiery, Inocome tax retruns etc. etc.