"Our nation is run by a constitution which has secularism as a pillar," the former Uttar Pradesh chief minister said.
"Whichever party is in the government is responsible to take care of the safety of the life and religious beliefs of people," she said.
Nearly 300 members of some 60 Muslim families living in a slum on Agra's outskirts reportedly embraced Hinduism Monday. The Bajrang Dal said it had organised the event.
Mayawati said: "There is a provision that there shall be no forced conversion. We got to know through the media that RSS' sister organisation Bajrang Dal has forcefully converted Muslims in Agra.
"They (Muslims) were lured. They (Bajrang Dal) took advantage of their poverty to convert them," alleged the Bahujan Samaj Party leader.
"This issue shall be taken up seriously. Although I know the (central) government will say it is a state subject," she added.
"If it is not stopped, it will cause communal tension in the whole country. The government must take strict action."
Minister of State for Parliamentary Affairs Mukhtar Abbas Naqvi said the government was committed to secular ideals.
Mayawati: Bajrang Dal took advantage of their poverty to convert them
"I want to clarify that we are as dedicated to harmony and secularism as anyone else. Secularism is not anyone's monopoly," he said. "As far as this incident is concerned, an FIR has been registered. Naming a particular organisation for political reasons is not right.
"I request (the chair to) expunge the name of the organisations specially the RSS. Whatever action has to be taken has to be taken by the state government," Naqvi said.
The opposition sought a clarification from Prime Minister Narendra Modi.
CPI-M leader Sitaram Yechury said: "The RSS has said that after 90 years they have their government in (Delhi). They say they will covert the nation into a Hindu nation. "People were misled, the government must make a statement," he said.
Congress leader Anand Sharma asked Deputy Chairman P.J. Kurien to direct the government to elicit the prime minister's views.
Kurien said: "If you want to raise the issue, there are rules."