SELECT
If MULTI_ORG_FLAG is set to 'Y' Then its Multi Org.
SELECT MULTI_ORG_FLAG FROM FND_PRODUCT_GROUPS
If MULTI_ORG_FLAG is set to 'N' Then its single Org.
U can check whether Multi - org is installed or not by using following query.
Select multi_org_flag from fnd_product_groups ;
If the result is
' Y ' then it is set to be multi - org.
' N ' then it is not set to be multi - org.
Cheers
Bonthu.