user: Question: In what Round with an Overall greater than 306 was the pick from the College of virginia tech?
Columns: ['Round', 'Pick #', 'Overall', 'Name', 'Position', 'College']
Types: ['real', 'real', 'real', 'text', 'text', 'text']
Sample row: [1.0, 1.0, 1.0, 'Aundray Bruce', 'Linebacker', 'Auburn']
SQL:

assistant: SELECT "Round" FROM "Table" WHERE "College" = 'virginia tech' AND "Overall" > 306.0;