The Crime Branch of the Delhi Police served the notice on Chandra and his son Puneet Goenka to join the probe on Saturday.
The moves comes a day after Chandra told the police that he is prepared to appear before them in connection with the alleged extortion bid by two senior editors of his channel within four days of notice.
Delhi Police had served two notices to Chandra last month asking him to join the investigations after the arrest of Zee Editors Sudhir Chaudhury and Samir Ahluwalia for their alleged extortion bid of Rs 100 crore from Jindal's company for not airing news damaging to it.
In a letter to Delhi Police through his lawyer R K Handoo, the Zee Group Chairman had claimed "vested interests" have created a public "mis-impression" that he is deliberately not joining investigations.
Terming the campaign as "vicious", "malafide" and "unwarranted", the letter said Chandra had informed the police on November 27 that he went ahead with his "pre-scheduled" meetings and engagements in India and abroad.
Investigators have told a local court earlier that they were treating him as an accused as he knew about the dealings between his employees and Congress MP Naveen Jindal's company.
Zee Group has denied the allegations and demanded the immediate release of its two senior journalists, alleging the police action was "illegal" and "designed for something else".
