oracle base in upgrades ie oracle/grid 12---->19

simple question

In an upgrade 12 ->19 oracle database/ oracle grid

Can the ORACLE_BASE BE DIFFERENT IN 12 VS 19??

Oracle 12c using Oracle Grid for restart and oracle 12c is to be upgraded to oracle 19 both grid and oracle.

Question is can ORACLE BASE be different for oracle/grid 12 c from ORACLE BASE for oracle/grid 19? Clear ORACLE HOME MUST BE DIFFERENT.

Querstion is what about ORACLE_BASE. example

for 12

/orainst/app/oracle

for 19

/oradata/app/oracle

grid

for 12

/orainst/app/grid

for 19

/oradata/app/grid

THAT OK? OR DOES BASE HAVE TO BE SAME?