asm_ora_home 
This parameter specifies the Oracle home of an ASM instance.
Syntax
asm_ora_home = <asm_home> | (<db_inst1>:<asm_home1>,
<db_inst2>:<asm_home2>, <db_inst3>:<asm_home3>, ...)
Default value: none
Example
Single instance:
asm_ora_home = /oracle/GRID/11202
RAC database:
asm_ora_home = (RAC001:/oracle/GRID/11202, RAC002:/oracle/GRID/11202,
RAC003:/oracle/GRID/11202, RAC004:/oracle/GRID/11202)