Speaking to SBS Punjabi Jayant Chitnis says, "It's not knowing what happened, that makes it so difficult."
"If he had called and said I'm ok, I need time, we would be fine. But a year on, we are none the wiser as to what happened that day."
The family were meant to go for a celebratory dinner for Jayant's 60th birthday on the day Tej disappeared.
What makes it even more unfathomable is that "he knew we had made that restaurant booking three months ago," says Jayant.
"When we are by ourselves, a million questions run through our minds - why did this happen, did we do something wrong, or could we have done something else. There are all these questions, but absolutely no answers," says Jayant, father of Tej.
"None of his friends have heard from Tej either. In fact they didn't even know that he didn't attend university for two years before he went missing."
"Obviously, it is a new friend that no one knows about who is helping him out, because Tej couldn't have survived for 12 months without anyone's help, " says Jayant.
Listen to the full interview with SBS Punjabi below:
Discussing Victoria Police efforts to trace Tej's car, Jayant says, "Tej drove a 2005 Volkswagen, and apparently there are 300 similar cars in Victoria."
"In fact there's a similar one in Healesville itself with a slightly different registration number and quite often people mistake that for Tej's car and report it."
"But so far, the police has not been able to trace Tej's car at all - unfortunately in Australia, we don't have chips in the license plate like they do in America.
"As it is, the car registration has now expired and no one will be able to drive it."
"But I'm an optimist and am very hopeful that we'll hear from him soon," Jayant adds. 'We are living in hope"
Meanwhile, the Missing Persons Advocacy Network has produced a touching video about Tej the person - not just Tej the missing person. A mural has been hand painted in an alleyway on Elizabeth St (in Melbourne city), to help jog people's memory about Tej and his car. It is an effort to make the missing "unmissable," as evident in this video.
The Chitnis family is very hopeful that the new campaign by MPAN to make Tej "unmissable" gives new momentum to the search for Tej, and that they can finally hope to receive the phone call for which they've been waiting for a year now.
"While we have found a way to continue living our lives, but there's always an awful feeling deep in the pit of the stomach," says Jayant.
"I don't what we'll do on April 27, and how we'll face the day, but all we want is some answers."