Complex sentence: Crocodiles are rare and inhabit only the backwaters of the Indus, the eastern Nara channel and some population of Marsh crocodiles can be very easily seen in the waters of Haleji Lake near Karachi.
Split into simpler sentences: Crocodiles are rare and inhabit only the backwaters of the Indus, the eastern Nara channel. Some population of Marsh crocodiles can be very easily seen in the waters of Haleji Lake near Karachi.