A 45-year-old Australian man has been arrested on charges of attempting to murder an Indian student working as a taxi driver in Melbourne, who is now battling for his life.

Parish Charles was remanded to custody on Wednesday on seven charges by the Melbourne Magistrates Court over the stabbing of Jalvinder Singh, 23, who continues to be in "critical condition" and is in "induced coma".

Charles' lawyer Rob Melasecca told the court his client had contracted HIV 20 years ago and had recently begun taking new medication. He said the accused had no memory of Tuesday morning's events.

Charles is charged with attempted murder, intentionally and recklessly causing serious injury, assault and car theft and was ordered to reappear for a hearing on July 23 by Magistrate Lance Martin.

Melasecca said his client had no criminal history, was horrified about what had occurred and needed help otherwise there would be "two victims".

"He's very much someone who is out of his comfort zone... does not know where he is, does not know why he's (here)," Melasecca said.

"His mental health is a very big question mark," Melasecca added.

A spokesman of the Royal Melbourne Hospital on Wednesday said Singh's condition had improved, though he was still in a serious condition in the intensive care unit.

Hundreds of cabbies poured into the streets for the second day on Wednesday and took off their shirts to protest against the attack.

Shouting "we want justice" and "shame, shame Victoria police", they blocked a busy intersection in Melbourne, disrupting vehicular movement. Some among them took off their shirts in a freezing morning.

Charles sat in the dock wearing blue rubber gloves. He had a shaved head, a goatee-style beard and appeared hunched over during the hearing, The Age reported.

"The difficulty is the victim in this matter is in an induced coma, so he's not able to tell us what happened," Melasecca told the court.

Charles said he had been suffering severe head pain, which he compared with an "electric shock".

Martin ordered that Charles be remanded at Melbourne Assessment Prison, where he would be assessed to see whether he should be transferred for more intensive treatment.

Police allege that Charles stabbed Singh while they were travelling in Clifton Hill and then dumped him in the street and took control of the car before crashing it into a power pole.

Melasecca said his client did not dispute the police version of events, but said his client's state of mind would be key to the case.

"He's in a terrible condition," he said. "This is not going to be a case about anything other than about his intent and his state of mind."