He was produced before MCOCA court that remanded him in police custody, a police statement said.
The 48-year-old Pillai, who heads an organised crime syndicate, was detained by Singapore early this year after Red Corner Notice was issued against him by Interpol in 2012, police said.
Efforts were made to extradite Pillai from Singapore by city's crime branch through proper correspondence and submission of papers.
"Pillai was extradited from Singapore after proper follow-ups at international level by the government of India. The extradition proposal was submitted through India's central agencies," Joint CP (Crime) Sanjay Saxena said.
More From This Section
"Pillai had stepped into the organised crime world to take the revenge of his father's death and is believed to have considerable influence in eastern suburbs of Vikhroli and Bhandup, where he used to extort money from builders," another senior official said.
In 2009, Pillai had demanded Rs 50 lakh extortion from a builder in Vikhroli. But when the builder refused to relent, Pillai's associates opened fire to kill him, although the builder escaped, the official said.
Cases of attempt to murder and extortion have been registered against Pillai in Vikhroli and Kanjurmarg police stations, police said.
Crime Branch officials said Pillai, an engineer, used to procure weapons from Sri Lanka's LTTE.