Start the database in mount mode (STARTUP MOUNT). Then isue the following:
ALTER DATABASE DATAFILE '/u02/oradata/index00100.dbf' OFFLINE;

If youur database is in NOARCHIVELOG mode, you must use
ALTER DATABASE DATAFILE '/u02/oradata/index00100.dbf' OFFLINE DROP;
instead.

After that you will be able to startup the database and drop the offended tablespace.