There is no such thing as a quota for Indonesians. Who told you that load of garbage?
They might not have any quota for WP holders, or quota for S pass holders or Sub-Quota's for PRCs, which, by the way, is the ONLY nationality based quota in MOM. Everything else is subject to either traditional sourced (for WPs and is made up of 7 nationalities).
This is subject to nationality quotas that are industry dependent but the quotas are not based on the countries allowable in that industry but on the total WPs allowed based on the company's total headcount. If you are trying to get a job in an industry that is not open to Indonesians, you will never get a visa for that industry as it's just not allowed.
For all the industries...
http://www.mom.gov.sg/passes-and-permit ... ific-rules
You will note that Indonesians are not allowed to have Work Permits with the exception of FDWs (Foreign Domestic Workers).
This means Indonesians are only allowed S passes or EPs. Neither of these have any ethnic quotas, only quota as a percentage of the total workforce of the company.
Do a search of the threads here. It's been gone over a number of times and the board has an excellent search function. Besides, it's past my bed time. I'm no long a spring chicken.