Solution
USB-6363 with BNC Termination (PN: 782258-01) has 16 BNC channels. The pin assign of AI 0 - 7 and 16 - 23 are the same with other type of USB-6363 as following.
For example, AI0 (BNC) consists of AI 0 (AI 0+ of the BNC) and AI 8 (AI 0- of the BNC). AI16 (BNC) consists of AI 16 (AI 16+ of the BNC) and AI 24 (AI 16- of the BNC).
Using 32 AI channels for single-end measurement, you need to have BNC to wire lead converter of some other things to use BNC + and - channel separately.