Well, if you're talking about Jatts, the Jatts were not "Muslims orginally".
They were simply Jatts. Their religion was not Hinduism, either (worship of the 3 devtas and their avtars plus fealty to Brahmins). Rather, they were ancestor-worshippers. That was their religion.
Some became (or were forced to become Muslims). Others became Sikhs. Still others became Hindus.
These days, a majority of Jatts are non-Sikhs (Muslims in Pakistan or Hindus in the eastern areas).