I know witnesses who learned Urdu to preach to Muslims. I don’t think they had much success here but I think there are Urdu groups in England. I know of one person with a Muslim background who got baptised in a nearby congregation but it caused a lot of problems in his family and don’t know if he is still a JW. He had some personal problems and was already a black sheep of the family even before he became a JW. He was baptised around 1998.
I just checked and there are Urdu groups in London, Birmingham and Glasgow listed on the JW website. There may be others. There are a couple of Arabic groups listed too.
It would be interesting to research, but my guess is that the Muslim country with the largest JW presence may be Indonesia. It would be difficult to tell how much of the preaching in Muslim majority countries is directed at Muslims but there must be at least some.