Dear Mr. Ahmad Rais siddiqi. Your statement about in ISLAM all equal is not true. I am giving you few lines from wikipedia site:
Historians such as Will Durant contend that Islam spread through violence. Sir Jadunath Sarkar contends that that several Muslim invaders were waging a systematic jihad against Hindus in India to the effect that "Every device short of massacre in cold blood was resorted to in order to convert heathen subjects. "In particular the records kept by al-Utbi, Mahmud al-Ghazni's secretary, in the Tarikh-i-Yamini document several episodes of bloody military campaigns. Hindus who converted to Islam however were not completely immune to persecution due to the Caste system among South Asian Muslims in India established by Ziauddin al-Barani in the Fatawa-i Jahandari., where they were regarded as an "Ajlaf" caste and subjected to discrimination by the "Ashraf" castes.