Methods, systems, and devices for wireless communications are described. Interference between random access channel (RACH) transmissions and Industrial Internet of Things (IIoT) transmissions may be avoided with a RACH occasion forbidden mask and a dynamic indication of availability of downlink retransmission resources. A user equipment (UE) may receive an indication of a RACH configuration and a forbidden mask associated with the RACH configuration. The UE may identify, from a set of random access occasions indicated by the RACH configuration, a subset of allowed random access occasions based on the forbidden mask. The UE may transmit a random access message during at least one allowed random access occasion of the subset. Additionally or alternatively, a base station may determine whether one or more transmissions on a component carrier (CC) were successful, and transmit downlink control information (DCI) indicating whether a set of random access occasions are available on the CC.