I'll assume for a second that you're Indian... let's say your brother were to become Muslim tomorrow. Would he be any less Indian after the fact? Or any less your brother? No he wouldn't. Muslims in India aren't Arabs who invaded and settled, they're Indians who converted. Go back far enough and you probably have a common, Indian ancestor with most of them.
>Prior to 1947, Hindus constituted between 14% to 23% of the population of what is now Pakistan, that is more than the current percentage of Muslims in India. Cities like Karachi (about 50%) and Lahore (roughly 30%) had sizeable number of Hindus. Today, as per the 1998 census, Hindus comprise a mere 1.6%.
Meanwhile the Muslim population in India has grown as a percentage.