The largest Muslim population in a country is in Indonesia, a nation home to 12.7% of the world's Muslims, followed by Pakistan (11.0%), and India (10.9%). About 20% of Muslims live in Arab countries. read more
from my knowledge there is infact Muslims living in India today but there was a big dispuit in between the religions of Islam and hindus and buddhists that eventually form the country of Pakistan which is a mojority of musliims. read more