According to a report at Politico, should Republicans want to they could delay the recording of the Electoral College votes in the Senate with procedural moves that would likely fail -- but would allow them to forestall the inevitable.
As Politico Playbook's Jake Sherman and Anna Palmer write, "Biden sources told us they became aware that there is a large batch of votes in Philadelphia that will put the former VP over the top in the state," before adding that should pave the way to the presidency.
However, as the report points out, that doesn't mean Republicans will admit defeat and let the political process to continue unimpeded.
As he notes, the Congressional Research Service explains that the Senate is scheduled to convene on Jan 6th, with Vice President Mike Pence presiding to count the votes, and that is where the "mischief" could begin.
"While the tellers announce the results, Members may object to the returns from any individual state as they are announced. Objections to individual state returns must be made in writing by at least one Member each of the Senate and House of Representatives. If an objection meets these requirements, the joint session recesses and the two houses separate and debate the question in their respective chambers for a maximum of two hours<" CRS reports. "The two houses then vote separately to accept or reject the objection. They then reassemble in joint session, and announce the results of their respective votes. An objection to a state’s electoral vote must be approved by both houses in order for any contested votes to be excluded.”
Politico Playbook notes that it is highly unlikely that both chambers of Congress would agree on any complaint and that it would just be grandstanding by Republicans that would be doomed to failure.
You can read more here.