It is also understood that India, which has been denied consular access to Jadhav 13 times, has again moved a request for access.
Asserting that the whole country's sentiment is with Jadhav, External Affairs Ministry spokesperson Gopal Baglay said the government will not spare any effort in securing justice for the "innocent" Indian national but refused to divulge details.
46-year-old Jadhav has been awarded death sentence by a Pakistani military court on charges of alleged "espionage and sabotage" activities.
"India has no knowledge of Kulbhushan Jadhav's location and his condition. We are making all efforts to get him back but we can't reveal the steps that will be taken to achieve it," he said.
The government is in touch with Pakistan through the Indian High Commission on this immensely important issue, he said.
Baglay said Jadhav is an innocent Indian who is a retired officer of the Indian Navy and these two things were conveyed to Pakistan in March 2016.
On reports of Jadhav carrying a fake passport, Baglay said, "We cannot ascertain anything since we did not have any consular access. Which kind of spy keeps an original passport with him so I have my doubts on any allegation of his being a spy...We need to know how he came to be in Pakistan in the first place."
India has been maintaining that Jadhav, who had legal business interest in Iran, was kidnapped by Pakistan authorities.
The trial of Jadhav was opaque and farcical, no due process was followed and all legal and international norms were defied, Baglay said.
The issue has triggered a fresh tension in Indo-Pak ties and India has warned Pakistan of the "consequences" Jadhav's hanging could have on their ties and vowed to go "out of the way" to save him amid pervasive outrage in the country.