Yes they did convert but their mind didn't changed beacuse they were used to do pooja and things and caste is based on Hinduism so it influenced them that's the thing You know Jinnah found of Pakistan? His dad was Gujarati Hindu his name was Poonjabhai something he used to sell fish for living but his family didn't allow coz they were vegetarians and he got angry and converted to Islam you see the root problem is with Hinduism itself that's why even Jinnah was so against Hinduism even though he was first generation Muslim and about Turks etc it's because of they don't want to mix their genes with Indians coz the offspring might look different and it happens everywhere so they don't allow mixing races that's different scenario