Bhariya, NVC will require all the documents (plus some additional documentations) you have mentioned later in the process. They will send you a listing of all the docs needed both from the beneficiary & petitioner (you) & it could be either original or a copy - either is fine for them. But you only send these documentations when they ask you for them - they will send you a letter detailing what they need during the last stage of the process.

For now you just pay D261; they will review this & mail the designated agent (you or lawyer whoever it is) with further forms & ask to pay immigrant visa fee for your beneficiary. At that point they will also ask you to submit an Avidavit of Support form. They will review it & then advise you what docs they need (birth cert, police record etc). It's a long process & you can't send them anything without them asking for it.

After they receive & review these dics they will schedule an appointment date for your relative at US Embassy KTM & give you with a list of accepted clinics in KTM for your relative to get vaccinated or tested to meet clinical requirements.

Hope this helps! Good luck.