When Zakir Hussain was produced before the Magistrate Pannerselvam, he told the court that he was not a terrorist and suddenly slashed his left hand with a blade.
He was immediately rushed to a government hospital, police said, adding that his condition was not critical.
Investigation was on to establish how Hussain, arrested on March 28 from his residence at nearby Tirunagar, managed to get the blade while in police custody.
The bomb was detected and defused before Advani's cavalcade crossed a bridge at Aalam Patti on October 28, 2011.