It will be much longer than 61 days for the legal challenges.
This will follow the established "Notice of Proposed Rulemaking" process. The proposed rules will be posted in the Federal Register, followed by a set time period for public comments. Then the agency has to read, summarize, and respond to each public comment. This will take 6 months at least.
Then the agency either withdraws or makes final the proposed rule.
At that point, once the proposed rule is adopted, that the litigation begins.
I think this falls under the desires of the protestors with the “Do something.” signs. Biden knows he hasn’t got the votes to do this in Congress. This is what you do when there’s nothing you can do.