ISRO's Next Generation Rocket System

The most powerful rocket that ISRO has is the GSMA Mark III or the SLS III. But in comparison with the other rockets that the world has, it's a light to medium launch vehicle. I don't know if ISro is working on such projects and what this status is. Is it in the conceptual stage? Are we anywhere close to testing them? In the future, let me see if I can talk to somebody from ISRO and find out what's actually happening.