Nambiar is deputy chief of Sena's Mira Bhayander unit.
Additional sessions judge V V Virkar granted him bail with sureties of Rs 30,000 and directed him to attend the police station every Saturday.
Nambiar, a three times corporator of the Mira Bhayander Municipal Corporation, had been arrested on September 5.
He is accused of misleading a minor teen-age girl and having a sexual relationship with her. The girl, who gave birth to a child recently, has been lodged at Bhiwandi remand home.