What are NCDs (Non-Convertible Debentures) and should I invest?

NCDs are corporate debt instruments offering fixed interest (9-12%) listed on exchanges. AAA-rated NCDs from large corporates are relatively safe. Lower-rated NCDs offer higher yields with credit risk. NCDs have defined tenure (2-5 years), pay quarterly or annual interest, and are taxed at slab rate. Good alternative to FD for 20-30% bracket investors.