Actually urgency to develop heavy launch GTO vehicle has gone away due to development of Electric propulsion satellites. The heaviest commercial satellites in GSO orbit were around six tonnes. With development of Electric satellites weight has fallen by almost 60% to 2.4 tonnes. similar thing happened with PSLV, isro was aiming at 1000 KG in SSO orbit and heavier version of PSLV can do 2000 kgs in SSO orbit, but due to induction of Israeli technology now the satellite weight around 500–600 KG. Off course some radar satellites are still in the range of 2000 KG.
Anyhow, Sce engine is massively delayed. There is no prospect of, completion of development, test launches, and then commercial use being completed soon, means that SCE engine based launch will be realised only in 2030.
Due to difficulty in engineering, the SCE of Ukrainian design, ISRO might rely on Russian SCE engines or even take Russian help in new SCE or Ukrainian SCE engine version.
Anyhow, even SCE Based on Kerosene engine is now slightly outdated even before development because the world is moving onto methox engine due to the success of SpaceX as methalox engines are inherently reusable.