rdisp/rfc_max_wait_time is a SAP Parameter attribute which is used to control Maximum wait time after load check information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
Quota for the maximum wait time after load check in the system. The wait
time is calculated based on the amount of available resources. The fewer
resources that are available, the longer the wait time.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.