E-TENDER FOR DESIGN, SUPPLY, INSTALLATION, TESTING & COMMISSIONING AND WARRANTY SERVICE OF DIGITAL DISPLAY SCREENS AND RELATED EQUIPMENT IN ALL 52 TRAINS OF CMRL FOR PROVIDING VISUAL AND AUDIO BROADCASTING OF AUTOMATIC ROUTE RELATED INFORMATION & ADVERTISEMENTS IN CMRL PHASE 1 AND PHASE 1 EXTENSION SECTIONS. IT IS ALSO CALLED AS RAVIS (ROUTE RELATED AUDIO AND VISUAL INFORMATION SYSTEM).