Do you mean "recover a RAC database"?
Answer is the same as a singe instance database. The only difference is that the recovery process might ask for archived logs from all the instances.
SQL> STARTUP MOUNT
ORACLE instance started.
Total System Global Area 289406976 bytes
Fixed Size 1301536 bytes
Variable Size 262677472 bytes
Database Buffers 25165824 bytes
Redo Buffers 262144 bytes
Database mounted.
SQL>
SQL> RECOVER DATABASE;
ORA-00283: recovery session canceled due to errors
ORA-00264: no recovery required
SQL> ALTER DATABASE OPEN;
Database altered.
Best regards.
Frank