Jetson Nano for three 4K camera input

I have seen in data sheet, Jetson Nano has three x4 MIPI CSI support and three active stream can be taken. But the maximum resolution was not mentioned. Is Jetson Nano is capable of taking three 4K camera together in a custom carrier board design?
How many internal ISP Nano has ?

Suppose can support 4k@30 without problem.