def calculate_top_capacities(data):
    """
    Calculate top capacities from given data.

    Args:
        data (list): List of tuples containing capacity metrics.

    Returns:
        tuple: Top capacity metrics as a tuple.
    """
    return max(data, key=lambda x: x[1])

# Example usage
data = [('v5_1768236144', 108217.11959687909, 721, 15009.3),
       ('v5_1768235312', 89435.63603047856, 734, 12184.7),
       ('v5_1768235983', 98379.19963352643, 987, 9967.5)]

top_capacity = calculate_top_capacities(data)
print(top_capacity)