THREAD : ISRO publication showing the Second Vehicle Assembly Building (SVAB). The render shows an unknown rocket inside the building. The rocket in SVAB isn't GSLV Mk3, but something bigger. Pic2 shows a VSSC render of HLV, there has been some talk about it in the media.

“One of the launch vehicles will look like the GSLV MK-3, but it will be much taller, almost 65 m, weighing 732.6 ton at lift-off and it is capable of putting a 10-tonne space plant in the communication orbit,” said Dr. S. Somanath, director of VSSC. https://rb.gy/r7cib7 

ISRO has a tender out for a transportation trailer for the SC120 semi-cryo stage. The SC120 stage comprises of SCE-200 engine & carries 120 tons of RP-1/LOX. It will replace the L110 stage of the GSLV Mk-3, which comprises of 2 Vikas engines & carries 110 tons of UDHM/N2O4.

There is also a tender out for a transportation trailer for an upcoming C32 cryogenic upper stage. It will use the CE-20 cryogenic engine and carry 32 tons of LH2/LOX. This stage will be replacing the C25 cryogenic stage, carrying 25 tons of LH2/LOX, in use with the GSLV Mk-3.

Dimensions of the various stages. As mentioned above, SC120 will replace the L110 & C32 will replace C25. The diameters are all the same. But there will be a increase in length of the GSLV Mk-3. The changes will take the height of the GSLV MK-3 to ~45.9 m from the current 43.4 m.

The new height(~45.9m) is nowhere near the height mentioned in the article(65m) posted above. Therefore the upgradation of the GSLV Mk-3 & the HLV must be separate projects. Maybe the HLV is a part of the ULV program & will use clustered SCE-200 engines instead of a single one.

By ISRO's estimates replacing the Vikas by a SCE-200 will take the payload of Mk-3 to 5 tons GTO from the current 4 tons. To take the payload to 10 tons GTO, clustered SCE-200 engines and a longer stage carrying far more propellent will be required. https://buff.ly/2EagF1G 

In 2018, Dr. S. Somanath attended the Toulouse Space Show in France & made a presentation there. There he showed a semi-cryo stage with 200 tons of propellent coming up in 2021. But the tender is for a 120 ton propellant carrying stage. So, what happened to this 200 ton stage ?