PER NDTV:
Terrorists came from Gujarat using fishing boats that run between Gujarat and Mumbai.
Gujarat is on the wide peninsula north of Mumbai (Also close to the Pakistan border). That explains hows they got close to Mumbai. The rubber crafts were apparently launched from the large fishing boat. They could have come from Kurachi to Gujarat by land.
Hmmm... Gujarat is a pretty large area. It runs from Pakistan down almost all the way down to Mumbai. Speedboats? Fishing boats? Rubber rafts? It will probably take a while to get all this sorted out...