From what I understand, if you entered the country legally, and you have not been out of status, you do not have to go outside when changing your status. i.e. before being on TPS, you were in some legal status like F1 or H1B. In this case, you need not exit the U.S. to apply for EB3.
If you were out of status for less than a year, you need to go back to Nepal and apply for GC from there.
If you were out of status for more than a year, according to the below link I found, apparently you will be subject to the "10 year bar" for re-entry to the U.S.
Hopefully you have not been out of status and if you have, it's less than a year.
I am not an attorney so do not take the above as 100% factual. Please consult with an experienced immigration attorney. Good luck!
Last edited: 10-Apr-16 04:19 PM
Last edited: 10-Apr-16 04:21 PM