That will depend on a lot of factors: the most two important are the DO you are interviewing in and the stage were your security clearance at.
- In some DO's, you can do the oath the same day as the interview, in others, they give you the Oath notice in the same day, in some more others, they will send it to you by mail to attend the next sechaduled oath if seat is available.
- If your name check is not cleared by the FBI by the time of the interview, then welcome to the club, your oath letter may arrive between 2 weeks and 2 years, depending in how fast the FBI process your name check and send it back to CIS.
So my advise to you, at the end of the interview ask the interviewing officer if your name check is completed or not. If it is completed, then congratulation, you are very close to obtaining your citizenship. If your name check is not completed, prepare yourself for a minmum of 6 months wait.
I hope that helped.
Steve
