Novel tricyclic carbazoles 4a-k were synthesized in one-pot employing sydnone derivatives 3a-k as masked hydrazines by the ring transformation in presence of conc. HCl and cyclohexanone. The title compounds were screened for anti-tubercular, anti cancer, DNA cleavage, antioxidant activity. MIC, GI50, LC50, TGI were evaluated. The title compounds have exhibited significant antitubercular, DNA cleavage and antioxidant activities and partial anticancer activity.