Barring more unexpected occurances, such as the very sad death of a Louisiana Congressman elect Luke Letlow, there will be 51 Republican Senators, 48 Democrat senators (including two independents who caucus with the Dems)
And there will be 210 Republicans and 222 Democrat Congresspersons. There are 3 seats that are still contested: NY-22 and Iowa-2 (Which are very tight, only 6 votes separate the candidates in Iowa) And Louisiana-5 Which is strongly Republican (this is the district won by Luke Letlow). These district won't have representation on Jan 3rd.
As noted in comments, It seems that the republican in Iowa-2 will be provisionally seated.
These are probably maximum numbers. It is possible some will be sick or self isolating or unable to take the oath for other reasons.