CREATE TABLE table_63990 ("Team #1" TEXT, "Agg." TEXT, "Team #2" TEXT, "1st leg" TEXT, "2nd leg" TEXT)

What was the 2nd leg score in the matchup with a team 2 of KK Borac?
SELECT "2nd leg" FROM table_63990 WHERE "Team #2" = 'kk borac'
SELECT "2nd leg" FROM "table_63990" WHERE "Team #2" = 'kk borac'