How to calculate ADC9207's SYSREF clock ?

Hi, the SYSREF signal can be a single pulse, a periodic sqauare wave, or a gapped periodic square wave. If you want to apply periodic wave, then the period should be an integer multiple of LMFC. Hope this answers your question.

Hi  : 

I designed the circuit with AD9207. and now need to coding to control clock.

I want to make sure that AD9207 with sample rate 6Gsps (jesd204c) and how could I calculate the SYSREF clock for AD9207?

Hi, the LMFC frequency depends on the ADC/DACCLK and few other JESD parameters. Could you review the "SYSREF Modes" section in the page29-30 of the Rev A UG-1578 document?