The group of ethnic and religious associations has issued a joint statement saying there is no case for changing sections 18C and 18D of the act.
Two days after the Government announced a parliamentary inquiry into freedom of speech, a diverse range of groups have called for leaving the most disputed parts of the act alone.
The signees include representatives from Greek, Armenian, Indigenous, Jewish, Indian, Arabic, Chinese, Vietnamese and Lebanese organisations.
The United Indian Association is one, and its president, John Kennedy, maintains the Racial Discrimination Act is doing the job it was intended to do.
"I can see so many people are discriminated against because of their colour here in this country, and, actually, I support, so much, multiculturalism and it is working very well. So we thought it is not necessary for parliament to repeal this Section 18C."
Mr Kennedy says he knows how it feels to be on the receiving end of racism.
He arrived in Australia in 1998 as a skilled migrant working in IT, and he says a colleague racially targeted him on his first day on the job.
He says he still remembers what the colleague said.
"'Why are you here? What made you think of here? You don't have a place in this country. Please go away, all right?' That's the first experience that I came into this country I had here."
Mr Kennedy says he was once abused over the phone when a client he rang assumed he was calling from India.
"When we speak to them, one of the customers was yelling at me over the phone, 'Are you calling from India? Are you calling from India? Where are you? Who are you?' Similar, like, similar notes on the phone."
The joint statement from the groups says sections 18c and 18D of the act have been key components of legislative and educative tools the communities have used to counter racism.
They say they fear a change to the substantive terms of those sections would send a signal that a degree of racism in public discourse is acceptable.
The signees say Australia's cultural diversity imposes an obligation on government to protect and encourage social cohesion and a failure to do so could be catastrophic.
While some Liberal MPs are among those wanting the Section 18C "insult and offend" provisions removed from the act, other Liberal MPs say they feel the act strikes the right balance.
Newly elected New South Wales MP Julian Leeser is among them.
"There are definitely people within the party who share my view that Section 18C achieves a good balance between allowing people the freedom of speech which is necessary in a democracy like Australia but also protecting racial minorities from racial vilification and racial slurs."
Mr Leeser has told the website The Conversation the complaint system through the Australian Human Rights Commission needs to be amended, though.
He argues there are not enough incentives to dismiss cases that have no reasonable prospect of success.
"What I'm suggesting happen is that, instead of the primary function (of the Australian Human Rights Commission) being 'investigate and conciliate,' that the primary function start being 'investigate and determine whether the case has a reasonable prospect of success.' And, if it doesn't, terminate as quickly as possible."
John Kennedy, with the United Indian Association, says Mr Leeser's suggestion seems practical.
"They can look at it and say, 'Okay, this may not go through,' so maybe it can stop that from going to the court and wasting time on it."
