Methods, systems, and devices for wireless communications are described. Random access channel (RACH) occasions may be scheduled on each component carrier (CC) of a carrier aggregation (CA) configuration that includes both a time division duplexing (TDD) TD Raid band and at least one frequency division duplexing (FDD) band based on a synchronization signal/physical broadcast channel block (SSB) received in the TDD band. In some cases, the TDD band may be used to configure the RACH occasions in same and/or different CCs. Additionally or alternatively, the FDD band may configure the RACH occasions on its uplink CC based on SSBs received on other CCs. Additionally, the RACH occasions may be configured such that the UE avoids unavailable uplink slots when transmitting a first RACH message in a RACH occasion.