I have applied for green card through marrying to US citizen. I sent Nepali marriage certificate (same page, but both in Nepali and English).

I received RIE saying that "submit a copy of the marriage certificate issued by the appropriate civil authority for you and the United States citizen Petitioner,...."

I don't know what to send next, should I sent the same marriage certificate that I sent before?

Help appreciated.

Thanks

Contact your congressman's local office (type in your zip code to search for the phone number in google). Ask to speak to his/her USCIS liaison. Explain your situation to that person, and have that person explain it to USCIS. Thing will go much more faster. USCIS liaison for your congressman's office will be able to find out why exactly they are requesting this (why they did not accept the last one) and what needs to be done now?

Note: be sure to contact the congressman's office, not the Senator's office.

Thanks for your help. Called them and explained my situation. Let's see what happens next.

Surprising part is, USCIS sent me print back that's on the travel.state.gov that says what kind of marriage certificate is available in Nepal. Either they misplace or mis-understood.

Going through Congressman is a better option than wasting numerous hours trying to get an answer from USCIS directly. I did the same thing for my mother. Congressman found out what's happening, and asked me to email the document again to his office and his office sent it to USCIS with an explanation. I did not mail anything to USCIS myself. The same document was accepted when congressman submitted it. 

Do you think that my EAD will be delayed because of this?

No idea, but whatever issue you have with USCIS or DHS, contact your congressman. They are free and better than lawyer.

How quick was the response from Congress man and USCIS?