You have to register for ERAS & NRMP and apply to at least one program to be able to participate in scramble. The list of programs participating in scramble will send through NRMP after the match day, most of these programs accept accept applications by ERAS, however people can send applications by fax or also calling them. Getting the list of these programs from other sources out of the NRMP is violation of NRMP rules, and you have to apply to these programs during the 2 days after match day, not before or after that.
Read the information in aamc.org & nrmp.org carefully.
from aamc.org:
Preparing for Scramble
Beginning at 12:00 p.m. EST on Tuesday of the Match Week, a brief period of time is set aside for those applicants who did not match, this time period is commonly known as the "Scramble." The Scramble gives applicants an opportunity to contact unfilled programs and possibly secure a position before Match Day.
During this period, applicants who did not match to a position attempt to fill remaining positions. ERAS is available for applicants to apply to a maximum of thirty (30) programs free of charge who meet the following criteria:
The applicant must have participated in ERAS during the regular season. This means you must have applied to (and paid for) at least one program.
The applicant's account must be paid in full no less than two weeks prior to the Scramble period.
Monday, March 13th - Applicants may sign into the NRMP web site at
www.nrmp.org with their AAMC ID number and password at 12:00 p.m. EST to find out if they matched to a position but not where. The message will be displayed immediately on the screen upon signing in and will be worded in such a way that the applicant will know whether they need to scramble and if so, which type of position they will need to scramble for on Tuesday, March 14th.
Tuesday, March 14th - Unmatched applicants who submitted a certified rank order list will be given access to the Dynamic List of Unfilled Programs at 12:00 p.m. EST on Tuesday of Match Week. Applicants may not contact unfilled programs prior to 12:00 p.m. EST that Tuesday. The list is updated by the NRMP every hour to reflect the number of remaining unfilled positions.
Thursday, March 16th - Match Day! Matched applicants may sign into the NRMP web site at 1:00 p.m. EST with their AAMC ID number and password to find out which institution they matched to through the formal match process. Their match program and specialty will be displayed on the screen immediately after signing in.
If you have already applied to a program, but that program still has unfilled positions, you may contact the program and inform them that you wish to be considered a Scramble applicant. That program will not count towards your thirty (30) Scramble programs on MyEras. Also, during Scramble, you may not apply to more than thirty (30) programs using MyEras, even if you wish to pay for them.