How to disable instance recovery in ORACLE?
Instance Recovery is necessary to get the database back to a consistent state after shutdown abort or some other abnormal shutdown event. Oracle is never going to let you open the database in an inconsistent state, so no, there is no possibility that you can disable it. If Oracle is crashing during Instance Recovery you need to get in touch with Oracle Support or revert to a backup.
The concepts guide has essential reading about instances and more particularly what Instance Recovery is and why it is sometimes needed:

If an instance of an open database fails, either because of a SHUTDOWN ABORT statement or abnormal termination, then the following situations can result:

Data blocks committed by a transaction are not written to the data files and appear only in the online redo log. These changes must be reapplied to the database.

The data files contains changes that had not been committed when the instance failed. These changes must be rolled back to ensure transactional consistency.


Instance recovery uses only online redo log files and current online data files to synchronize the data files and ensure that they are consistent.

If the Instance Recovery crash is caused by a corrupt datafile you could mount the instance, drop the offending datafile and then open the database - but you will lose the tablespace that file is in.