ORA-00600: internal error code, arguments: [ktecgetsh-inc], [2], [], [], [], [], [], []
Non-fatal internal error happenned while SMON was doing temporary segment drop.
SMON encountered 2 out of maximum 100 non-fatal internal errors.

1  set event 10061 in the pfile to turn off  SMON from cleaning temp segments.  
This will keep the database from crashing after SMON tries 100 times to clean the segment.

alter system set event="10061 trace name context forever, level 10" scope=spfile;

2 find temporary segment name,header_file 
select segment_name,segment_type,header_file from dba_segments where segment_type='TEMPORARY'; 
SEGMENT_NAME SEGMENT_TYPE
-------------------    -----------------------
98.110124                TEMPORARY             98.110124 <----------  datafile and block number

3 Find tablespace_name and mark the segment as corrupted:
select segment_name,tablespace_name from dba_segments where segment_name=&segment_name;
exec dbms_space_admin.segment_corrupt('<tablespace name>',98,110124)

4. Drop the segment
exec dbms_space_admin.segment_drop_corrupt('<tablespace name>',98,110124)

5. if have the bitmap index then rebuild all the bitmap indexes
exec dbms_space_admin.tablespace_rebuild_bitmaps('<tablespace name>');                                                                      

6. Remove event 10061 from pfile and bounce database
exec dbms_space_admin.tablespace_verify ('<tablespace name>');
alter system set event="10061 trace name context off" scope=spfile;