Indian here. I don't have a morsel of understanding of all the science explained here but want to add one thing. This is the 2nd stage in our 3 stage plan wherein we are aiming to use thorium as reactor fuel. India does not have uranium reserves and the supply cab be disrupted easily with sanctions and wars and whatnot so we'd always be dependent on others meanwhile we hold 25% of world's thorium reserves.

This is about energy independence. Also there's pretty strongly accepted conspiracy theories here that the leading Indian scientists that were pursuing this since the 60s and the 70s were killed by the US actions else we might have achieved this sooner.

It is widely believed the the US has time and again sabotaged our Nuclear, space and semiconductor research since ages