Gandhi's main tool in seeking independence for India was "Nonviolent protest"
This was widely known as "Satyagraha" in India, and it means "holding firmly to truth" and it is a form of nonviolence activities or protest against injustice or actions considered bad.
During Mahatma Gandhi's lifetime, the major means at which he seeks independence for India is through Nonviolence protest. He also used nonviolent protests against racial discrimination and the caste system in India.