If you are creating SMALLFILE datafile (default) with 8k blocks with datafile size greater than 32 GB than oracle will pop up with ORA-03206 error.
Because oracle will allow only up to 32 GB of datafile size limit with 8k blocks, maximum data blocks per datafile : 2^22 -1 = 4194303. So oracle simply won’t allow you in this case.
More than 32 GB datafile with 8k blocks than your datafile should be create with BIGFILE keyword.
Calculations are as follows:
Oracle allows max number of datafile is 65533 and Maximum data blocks per datafile is 2^22 -1 = 4194303 blocks.