โค้ชคนไหนได้รองแชมป์ภาคอีสานและคะแนน 6°3?
Which Coach has a Runner-up of northeastern and a Score of 6–3?
df = pd.DataFrame(columns=['coach', 'runner_up', 'score'])
df[(df['runner_up'] == 'northeastern') & (df['score'] == '6–3')]['coach']