From D3Hoops.com

How many D3 teams go from each region?

It doesn't work that way anymore. Now the Pool B (independents)  and C (at-large) bids are made on a national basis, meaning it is possible that nine teams could go from the West and only three teams from the East.

In men's: Two teams get first-round byes. In normal tournament years, the teams that play off to face those top seeds will meet in one of Thursday's two first-round games, which would in theory be games between No. 8 and No. 9 seeds. The other 52 teams meet in 13 four-team regionals on Friday and Saturday, effectively stripping home-court advantage from 13 teams that would otherwise have earned it in previous years.

Also, as soon as there are 416 eligible D3 schools, the tournament will expand to 64 teams. There are currently 407 schools