Explanation:

In 1972, Binod Bihari Mahato, Shibu Soren and A. K. Roy founded Jharkhand Mukti Morcha. Nirmal Mahto founded All Jharkhand Students Union. They spearheaded movement for separate state of Jharkhand. AJSU introduced elements of violence in the movement and called for bycott of election while JMM opposed it. Due to differences these party parted away from each other. There was a provision for limited internal autonomy in the hill area of Assam. Other tribal area were covered by the fifth schedule of the constitution.