Hi Alexis,
According to testing policies of Check Point, you cannot take the same exam twice (if you already passed it).
If you are trying to retake 156-315.77, probably gonna get an error like this:
Also those R7X certifications will probalbly be retired this year, with a 90 days notice according to other posts here in the forum.
If you're experienced with Check Point you could go for CCSM on R77 156-115.77 before the testing time expires.
The best you can do is take the CCSE Update for R80: 156-915.80
Regards.