Step 1: What is RTIS?
Real-Time Train Information System (RTIS) is a technology that provides automatic, real-time data about train movement timing using satellite communication.
Step 2: Role of ISRO
ISRO developed RTIS by utilizing its satellite technology to enhance railway operations and provide accurate train information to passengers and authorities.
Step 3: Other organizations
- CRIS and IRISET are related to railways but RTIS development is credited to ISRO.
- BEL is a defense electronics company.
Thus, Option (A) Indian Space Research Organisation (ISRO) is correct.