The Hindu ceremony is understood to be planned to take place from Sunday.
The organisation said while it supports freedom to practice one's religion, it was "highly ironic and disingenuous" that a family facing numerous allegations of fraud and corruption would host the religious function, "given that the deity being honoured is Lord Krishna who in Hindu scriptures teaches about the evils of greed and seeking of wealth".
"This kind of public religious discourse is usually intended to encourage devotees to act in the interest of humanity and public good," it said in a statement.
"JAI believes that the teachings of Lord Krishna are in direct contrast to the actions and practices of the Gupta family. Whilst we respect the rights of the devotees to worship, we believe that perpetual wrongdoers must not use religion to conceal their nefarious deeds or as some kind of public relations exercise to turn the tide of public opinion."
It called on Hindu priests, leaders and organisations to boycott the event and to rather "engage with the Gupta family through the writing of letters, requesting that they choose the path of righteousness".
"The Gupta family has been dominating the headlines of South African media for all the wrong reasons. They have been at the centre of almost all procurement scandals at State Owned Entities, Denel, Transnet and Eskom, not to mention the State of Capture Report by former Public Protector, Thuli Madonsela.
"The Gupta name has become synonymous with corrupt relationships and underhanded dealings and is recognised even by ordinary citizens who are not in the political domain. This special kind of ubiquity has resulted in a surge of anger and antagonism towards the family by South Africans who believe that the Guptas are a corrupting force."
It said it "cannot be right that the Guptas be allowed to pretend at being God fearing and humble people".
News24 was unable to reach the Gupta family spokesperson for comment. -- News24