Here is a sample Request letter for Non Objection Certificate (NOC) to apply for Passport and visa for a family member to join them abroad.

DOWNLOADNOC REQUEST

From,
NAME & CURRENT ADDRESS

To,
THE COMMISSIONER OF POLICE
ADDRESS

Sub: Request for NOC to apply for Passport and visa for my Father (NAME)

Dear Sir/Madam,
I, NAME, working as a Software Engineer in [COMPANY NAME], located at [ADDRESS]. I would like to invite my Father [NAME], to visit USA for to meet my family. He will be staying with me at my home at the above-mentioned address.

I will be responsible for their travel arrangements and bear all the expenses including the ticket, stay and medical insurance. I will make sure that he leaves United States before the expiration of his authorized stay as per the Immigration authorities and will abide to the local and national laws.
I respectfully request you to provide us the NOC to proceed with the necessary Passport and Visa paper work.

Thanking you,

Yours Sincerely,
(NAME)
DATE