doing a little research;
Of the teams that have won a NCAA Championship (dating back to 1955), every team has had a player on their team that eventually was drafted in the top 30, and played in the NBA.
Over 80% of the teams have had multiple players.
I used top 30 as that is now the cutoff for first round picks. Back in the early 60's, the 30th pick would have been third round.
But every team prior to Indiana in 1987, had a player drafted in the top 10.
Actually only 8 of 68 teams did not have an eventual top 10 draftee.