The RTC macros take the frequency parameter because RT does not know about the clock frequency, only about the systick frequency. It is HAL that knows about clock settings and RT cannot depend on HAL.
@sabdulqadir
Also trying to understand what delays should be used in the LLDs.
There are RTC-like functions in OSAL, very similar to those in RT, from drivers you should use OSAL services only.
Giovanni