Question: who plays the lead main role in 'delhi 6'
[{'answer': 'Abhishek Bachchan', 'provenance': [{'wikipedia_id': '20724748', 'title': 'Delhi-6', 'start_paragraph_id': 1, 'start_character': 93, 'end_paragraph_id': 1, 'end_character': 110, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]