Technically a simple majority (51 votes) is all that is needed for confirmation, however, 60 votes are needed for a ‘cloture’ vote to override a filibuster and get a stalled nomination to a vote...So if a vote comes up without a filibuster attempt then all that is needed is 51 votes...
The Senate sets its on rules for the session. They can make a no filibuster rule. Just as sure that I am that if the Democrats were in the majority, but did not have the numbers to break a filibuster, they would enact a no filibuster rule. I have the same confidence that the Republicans will enact a filibuster rule. But the Democrats have John McCain, his girlfriend Lindsey [Linda] Graham, Jeff Flake, etal masquerading as Republicans. Breaking their cover as needed from time to time.