could we use Twinax cable to connect UCS6140XP to CIsco Switch 3750X 10G module?
Yes you can.
The 10G module is SFP+ and the Twinax cable is SFP+ direct attached.
have you used in production or tested before
Unfortunately no, but there is no reason for not functioning. What are your considerations?
yes, I used it in production just 2 weeks ago. I connected a pair of 6120s to a pair of 3750Xs with twinax cables and it worked great.
Thank you very much for your confirmation! I will build the similar solution in the following few weeks.
Thank you very much!