The judgment in the American Center attack case of January 2002, in which Dubai-based don Aftab Ansari is the main accused, is scheduled to be delivered by a city court on Tuesday.
Aftab and 12 others, including a Pakistani national, were charge sheeted for murder, conspiracy and waging war against the country.
Five police personnel were killed and 20 others were injured in the terrorist act.
The judgment would be delivered against Aftab and eight of his associates. Three accused are still at large.
Security has been tightened and the police are keeping vigil on important buildings and at entry points to the metropolis.
Chief Judicial Magistrate Basudeb Majumdar conducted the trial in the high-security Presidency Jail. The trial commenced after the filing of the charge sheet on April 26, 2002. Public Prosecutor Ashok Bakshi said
123 witnesses were examined during the trial.
Aftab was tried on the jail premises in a special court after the
Calcutta high court granted permission following a request from the West Bengal government.
The prosecution had claimed it was risky to ferry Aftab to and from courts as he could try to flee from custody during transit.
Aftab is also the main accused in the kidnapping of shoe baron Partha Roy Burman in 2001.