Yoga that integrates Hatha Yoga, Pranayama, Meditation, and Mantra Chanting will be best for stress relief. When all these aspects are integrated we work at the level of the mind, body, breath, and energy. Regular Practice will bring about a change in inner chemistry. This will bring about more control over thoughts and emotions. This can lead to stress relief.
Yoga is the most effective way to get stress relief because it is a process that includes natural processes of movement, breathing, and sounds to work with the deeper layers of oneself.